Free
$0no card needed
- The Daily, every day
- 36 practice questions a day, each with an explanation: 12 easy, 12 medium, 12 hard
- Full-length Test A and Challenge Test 1
- All 1,023 vocabulary words: browse, flashcards and quiz
Digital SAT practice
Reach your peak.
A quick run every day, an explanation for every question, and full-length tests on official timing.
Free, no card. You also get 36 practice questions a day: 12 easy, 12 medium and 12 hard.
The DailySTEP 1
- Three hearts. A miss costs one.
- Streaks pay. ×2 from three in a row, ×3 from six.
- Your longest streak. Beat it tomorrow.
Full-length tests
The real test, rehearsed.
98 questions across four modules, in the digital SAT’s order and on its timing, with a highlighter, a question map and a timer you can see.
How it works
One run a day. One skill at a time.
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1
Play the Daily.
A quick run with three hearts. String right answers together and the questions get harder and the points multiply.
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2
Miss one, learn why.
Every question is tagged by domain and skill, and every answer comes with an explanation.
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3
Drill that skill.
Practice any single skill at any difficulty, or just the questions you got wrong.
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4
Beat your best.
Come back tomorrow and climb. Progress shows your accuracy and your strongest skills.
Built around the real SAT blueprint.
Every question is tagged by section, domain, skill and difficulty, so you can practice exactly what you need. Full tests run like test day: two Reading & Writing modules, a break, then two Math modules.
Free daily practice
12 easy, 12 medium and 12 hard questions free every day, each with a full explanation. Filter by section, domain, skill and difficulty. Resets at midnight.
Real SAT timing
Take any test on official timing, extended 1.5× time, or untimed to focus purely on accuracy.
Adaptive full-length tests
Four modules in official order. The second module of each section adapts to how you did on the first.
Vocabulary
1,023 essential SAT words. Browse the list, flip flashcards, or quiz yourself.
Your progress
Accuracy across daily practice and full tests, your strongest skills, and the ones that need the most help.
Games
PEAK Survivor, Hole and Peak Defense: three games powered by SAT practice questions.
Explanations
Every answer, explained.
Not just the right letter: how to get there, and why the tempting answer is wrong.
MathProblem-Solving and Data AnalysisHard
A store raises the price of a jacket by 20%. Later, it lowers the new price by 20%. The final price is what percent of the original price?
A80%
B96%Correct
C100%The trap
D104%
Check with $100: $100→then$120→then$96
Turn each change into a multiplier.
Up 20% means × 1.20. Down 20% means × 0.80.
Apply them in order.
1.20 × 0.80 = 0.96
Read the answer.
The final price is 96% of the original. That’s B.
Why not 100%?
The 20% cut is taken from the higher price, so it removes more than the 20% increase added.
Test day
What test day looks like.
Every Peakscor full test follows this order. In the standard tests, the second module of each section adapts to how you did on the first.
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Reading & Writing · Module 1
27 questions32 min
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Reading & Writing · Module 2
27 questions32 min
Adapts to how you did on Module 1. -
Break
10 min
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Math · Module 1
22 questions35 min
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Math · Module 2
22 questions35 min
Adapts to how you did on Module 1.
98 questions · 2 hr 14 min of testing, plus the break
Peakscor by the numbers
- 36free practice questions every day
- 98questions in every full-length test
- 1,023SAT vocabulary words
- 1.5×extended-time option on every test
Plans
Free every day. Pro when you’re serious.
The free plan is the real thing, not a trial. Pro removes the limits. Peak adds the full course and a plan to test day.
Pro
$20a month, or $200 a year
- Everything in Free
- Unlimited practice, no daily limit
- Every full-length test and Challenge test
Peak
$29a month, or $280 a year
- Everything in Pro
- The full Learn course: every lesson and mastery quiz
- Peak Plan, day by day to test day
Prices in US dollars. Cancel anytime.
FAQ
Questions, answered.
The Daily, plus 36 practice questions every day: 12 easy, 12 medium and 12 hard, each with a full explanation. Full-length Test A, Challenge Test 1 and all 1,023 vocabulary words are free too. No card needed.
Pro is $20 a month or $200 a year: unlimited practice with no daily limit, plus every full-length test and Challenge test. Peak is $29 a month or $280 a year: everything in Pro, plus the full Learn course and Peak Plan. Cancel anytime from your account.
98 questions across four modules, in the digital SAT’s order: Reading & Writing Module 1 and Module 2 (27 questions each), a 10-minute break, then Math Module 1 and Module 2 (22 questions each). On official timing that’s 2 hr 14 min of testing. You get estimated section scores and a total at the end.
Yes. In the standard full-length tests, Module 2 of each section is the harder version if you get 60% or more of Module 1 right, and the easier version if you don’t. Challenge tests use the hardest material throughout.
Official timing, extended 1.5× time, or untimed, on every test, including the free ones. Extended time allows 48 minutes for each Reading & Writing module and about 52 for each Math module. Untimed removes the clock so you can focus on accuracy.
A quick run with three hearts. Each right answer builds your streak: the questions get harder as it grows, and your points multiply (×2 from three in a row, ×3 from six). A miss costs a heart and drops you back to easy. Best is your longest streak.
Every day at midnight. You get a fresh 12 easy, 12 medium and 12 hard.
No. Peakscor is an independent SAT practice tool, not affiliated with the College Board. Scores shown are estimates.
Your next point starts today.
Free, no card.
Circles · Lesson 2
Central and inscribed angles
An inscribed angle has its vertex on the circle, and its sides are two chords (segments that join two points of the circle). Like a central angle, it opens onto an arc: the arc between its two sides, on the far side of the circle from its vertex. The measure of an arc, in degrees, is the measure of the central angle that cuts it off.
The inscribed angle rule: an inscribed angle is half the central angle that cuts off the same arc. In the figure below, central angle AOB is 100°, and inscribed angle ACB, which opens onto the same arc AB, is 50°. Any inscribed angle with its vertex on the longer arc from A to B opens onto arc AB too, so it also measures 50°, wherever its vertex sits.
Angles in a semicircle: a diameter cuts the circle into two semicircles, each an arc of 180°. An inscribed angle whose sides run to the two ends of a diameter opens onto a semicircle, so it is . If a triangle has a diameter as one side and its third vertex on the circle, the angle at that third vertex is a right angle.
Radii are equal. A triangle with two radii as sides, such as triangle AOB, is isosceles, so its two angles at the circle are equal. Many angle questions combine this with the inscribed angle rule and the 180° sum of a triangle's angles.
Worked example Easy
In the circle shown, O is the center, and points A, B and C lie on the circle. Angle ACB measures 34°. What is the value of ?
- Answer
How to solve it
- Angle ACB is an inscribed angle: its vertex C is on the circle. It opens onto arc AB.
- Angle AOB is the central angle that cuts off the same arc AB.
- An inscribed angle is half the central angle, so the central angle is twice the inscribed angle: .
Why each choice is right or wrong
- A. Incorrect. This halves 34 instead of doubling it, which gives 17. The inscribed angle is the half; the central angle is twice as big: .
- B. Incorrect. 34 would be right only for another inscribed angle. Two inscribed angles on the same arc are equal, but a central angle is twice an inscribed angle on the same arc.
- C. Correct. Central angle AOB and inscribed angle ACB cut off the same arc AB, so .
- D. Incorrect. This treats the angles as supplementary: . Nothing here makes the two angles add up to 180°; the central angle is twice the inscribed angle.
Worked example Medium
In the circle shown, O is the center, and points A, B and C lie on the circle. Angle OAB measures 32°. What is the measure of angle ACB?
- Answer
How to solve it
- OA and OB are both radii, so triangle AOB is isosceles, and angle OBA equals angle OAB: 32°.
- The angles of triangle AOB add up to 180°, so angle AOB is degrees.
- Angle ACB is inscribed and opens onto the same arc AB, so it is half of 116°: 58°.
Why each choice is right or wrong
- A. Incorrect. This assumes angle ACB equals angle OAB, 32°. Angle OAB is an angle of triangle AOB, not an angle on the circle that opens onto arc AB, so nothing makes them equal. Use it to find the central angle first.
- B. Correct. The isosceles triangle AOB has two 32° angles, so angle AOB is degrees. Inscribed angle ACB opens onto the same arc, so it is half of that: 58°.
- C. Incorrect. This doubles 32° to get 64°, as if angle OAB opened onto arc AB. It doesn't: its side AO points through the center, so doubling 32° gives the arc from B to the far end of the diameter through A, not arc AB. The isosceles triangle gives angle AOB = 116°, and half of that is 58°.
- D. Incorrect. 116° is the central angle AOB. Angle ACB is inscribed, so it is half of that, 58°.
Trap Doubling when you should halve
For the same arc, central angle = 2 × inscribed angle, so the inscribed angle is the smaller one. When you're unsure which way to go, check the figure: of two angles that open onto the same arc, the one with its vertex at the center is the bigger.
Trap Using the wrong arc
An inscribed angle is half of the arc between its sides, on the far side of the circle from its vertex. If the vertex is on the shorter arc between two points, the angle opens onto the longer arc, which is 360° minus the shorter one, and the angle is obtuse.
Trap Missing the unmarked right angle
When one side of a triangle is a diameter and the third vertex is on the circle, the angle at that vertex is 90° even if the figure doesn't mark it. That right angle often unlocks the 180° sum or the Pythagorean theorem.
Desmos When Desmos isn’t faster
Angle questions are solved on the figure: spotting which angle is inscribed, which is central and which triangle is isosceles. Desmos can't see the figure, so work these by hand.
The arithmetic is short, such as and , so typing it into Desmos saves no time.
Practice
Choose a section, then practice a whole domain or drill a single skill.
Full-length tests
Each test mirrors the digital SAT: 98 questions across four modules, 2 hr 14 min on official timing.
A little harder than the real SAT. These tests can run slightly tougher than test day, which makes them good practice: if you can handle these, the real one should feel easier. No question appears in more than one test, Challenge Tests included.
Challenge Tests Hardest of the hardest
Same 98-question format, but every question is drawn from the toughest SAT material: Challenging-tier math throughout and the hardest reading.
Vocab
Study the classic SAT vocabulary list. Browse, flip flashcards, or quiz yourself.
Free every day. Pro when you're serious.
Practice free every day. Pro removes the limits. Peak adds the full course and a plan to test day.
FREE
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- ✓ 12 easy + 12 medium + 12 hard daily
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- ✓ Test A and Challenge Test 1
- ✓ The first lesson of every Learn module
PRO
$200/ year
About $16.67 a month, save $40
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Full course and plan
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