Geometry solver app · Available now on Android

Every geometry step and theorem, explained.

From right triangles and circle chords to area, volume, and multi-step geometry proofs, Stemulus breaks down both the calculation and the geometric reason behind every step, then generates practice problems from your saved homework.

iPhone, iPad, and Mac: coming soon to the App Store.

10 free scan credits to start. No sign-in needed.

Geometry

A right triangle has legs a = 6 and b = 8. Find the hypotenuse c and area A.

Step by step.

Apply the Pythagorean theorem c² = 6² + 8² = 36 + 64 = 100 In a right triangle, the square of the hypotenuse equals the sum of the squares of the two legs (a² + b² = c²).
Take the positive square root for length c = √100 = 10 Side lengths are positive, so the hypotenuse is 10 units (a 3-4-5 Pythagorean triple scaled by 2).
Calculate the triangle's area and check A = ½(6)(8) = 24 Using A = ½bh gives 24 square units, and 6² + 8² = 10² confirms the side relationship.

Solution

c = 10, A = 24

Arithmetic checks passed

Why geometry needs more than a calculator

See the theorem and the algebra together.

In geometry, getting the number is only half the credit. Teachers grade on which postulate, theorem, or property justifies each step.

Each step states the geometric reason

Whether a problem uses supplementary angles, triangle congruence (SSS, SAS, ASA), similar triangles, or the Pythagorean theorem, every numbered step pairs the equation with a plain-English explanation of why it applies.

Arithmetic and substitution checks

Once unknown angles or side lengths are solved, Stemulus checks supported calculations by plugging values back into angle-sum or side-length equations.

Scan from your worksheet or type it in

Use the Android camera scanner to capture geometry word problems and algebraic angle setups, preview the crop for free, and check when ready.

Copy LaTeX for clean notes

Copy angle equations, radical expressions, and coordinate geometry formulas as LaTeX, or save your own attempt alongside the worked solution.

Geometry coverage

Built for high school and college geometry topics.

Stemulus handles both deductive geometric reasoning and analytic/coordinate geometry.

Triangles & Polygons

Congruence, Similarity & Right Triangles

Interior and exterior angle sums, isosceles and equilateral properties, similar-triangle proportions, Pythagorean theorem, and special right triangles (30-60-90, 45-45-90).

Circles & Arcs

Central Angles, Inscribed Angles & Chords

Arc length, sector area, tangent-radius relationships, intersecting chords and secants, and equations of a circle in standard and general form.

Proofs, Area & 3D Volume

Coordinate Geometry, Solids & Proof Steps

Distance, midpoint, and slope formulas, parallel and perpendicular lines, two-column proof justification steps, and surface area and volume of prisms, cylinders, cones, and spheres.

Prepare for geometry exams

Turn geometry homework into a theorem study guide.

01 · Save & Tag

Group problems by chapter or unit

Save checked geometry problems into an assignment (like 'Unit 4: Similar Triangles & Proofs') and mark tricky ones Still stuck or Review later.
02 · Study guide

Generate a formula and theorem guide

Build a study guide from your saved assignment that summarizes the exact theorems, postulates, and area/volume formulas used in your homework, with worked examples linked back to your original problems.
03 · Practice

Test yourself on three new geometry questions

Run a practice round with progressive hints one at a time. Enter your answer to check it before revealing the full worked solution.
04 · Offline

Review theorems and practice sets offline

All saved solutions, study guides, and practice sets open for free and work offline on your Android device.

Why a dedicated geometry study workflow beats a basic answer scanner

Most generic math calculators fail on geometry homework because geometry combines spatial theorems (like alternate interior angles or inscribed angle relationships) with algebraic equations. If an app only spits out x = 14 without stating why two expressions are equal or supplementary, you are left guessing on the next quiz.

With Stemulus on Android, you can scan or type the problem, verify the setup in step 01, see the algebraic steps and substitution check, and then generate a custom STEM Study Guide & Practice Round before your chapter test. Also taking science courses? Check out our Physics Solver App and Chemistry Solver App.

Pricing

Start free, then pay the way you study.

No sign-in is needed to check problems or subscribe. Every new account starts with 10 free scan credits. Link an Apple or Google account when you want to use your access on other platforms.

Subscription

Stemulus Pro

$4.99 per week

100 problem checks or study generations per rolling seven days
Each check becomes available again seven days after you use it
A failed generation returns its allowance
Renews weekly until canceled

One-time purchase

50 Scan Credits

$2.99 once

One credit checks one problem
No subscription, buy another pack when you need it
Opening saved solutions, guides and practice never uses a credit

US prices shown; your local price appears in the App Store or Google Play before you buy. A problem check uses one scan credit. For people without a subscription, generating a study guide or practice set also uses one scan credit, disclosed before you confirm, and a failed generation returns it. The subscription renews automatically until canceled; manage or cancel it in your App Store account or in Google Play. No free trial is offered.

Questions & Answers

Frequently asked questions

Can Stemulus help with geometry proofs as well as calculations?

Yes. Because every step in Stemulus includes a title, the mathematical expression, and a sentence explaining why that step holds, it is ideal for understanding the logical chain behind geometric proofs and algebraic angle setups.

Is the geometry solver app free to try on Android?

Yes. Every new user gets 10 free scan credits on Android with no sign-in required. After that, you can buy 50 Scan Credits for $2.99 once (no subscription) or subscribe to Stemulus Pro for $4.99/week.

Does Stemulus handle trigonometry and coordinate geometry too?

Yes. Stemulus covers right-triangle trigonometry (sine, cosine, tangent, law of sines, law of cosines), trigonometric identities, and coordinate geometry alongside plane and solid geometry.

Available now on Android. Coming to iPhone, iPad, and Mac.

Stemulus requires Android 8.0 or later, or iOS 26.5, iPadOS 26.5, or macOS 26.5 or later, and is available in English.