Triangle Solver: Free AI Help for Sides, Angles & Area

Triangle Solver

Triangles are one part of the geometry and trigonometry curriculum. For algebra and more, visit the full AI Math Solver.

Missing a side, an angle, or the area of a triangle? Our free triangle solver no sign up tool identifies whether you need the Pythagorean theorem, the Law of Sines, or the Law of Cosines, then walks through the calculation step by step.

Free, no sign-up Step-by-step, not just answers Photo & PDF upload 38 languages
How It Works

How to Use the Triangle Solver

Every triangle problem has a right tool for the job. Our solver picks it and shows exactly how it's applied.

1

Input What You Know

Type in the known sides and angles of your triangle and what you need to find.

2

Upload for Instant Analysis

Snap a photo of your triangle diagram or worksheet and the solver will read and process it automatically.

3

Step-by-Step Breakdown

See the correct theorem or law selected and applied step by step, not just the final side or angle.

What It Solves

What Our Triangle Solver Covers

From right triangles to oblique ones, this solver covers the full range of triangle problems taught in K-12 math.

Pythagorean Theorem

Find a missing side of a right triangle and check whether a triangle is a right triangle.

Law of Sines

Solve for missing sides or angles in any triangle when you know two angles and a side, or two sides and an angle.

Law of Cosines

Solve for a missing side or angle when you know three sides, or two sides and the included angle.

Area of a Triangle

Calculate area using base and height, or Heron's formula when only the three sides are known.

Congruence & Similarity

Prove triangles congruent or similar using SSS, SAS, ASA, and AA criteria.

Special Right Triangles

Work with 30-60-90 and 45-45-90 triangles using their fixed side-length ratios.

By Academic Level

Triangle Support for Every Student, Anytime

Triangle problems evolve from the Pythagorean theorem to full trigonometric laws. Our tool matches the method to your level.

Grades 6-8

Middle School: The Pythagorean Theorem

Master finding a missing side of a right triangle and recognizing right triangles from side lengths.

High School Geometry & Trig

High School: Law of Sines & Cosines

Solve any triangle, not just right triangles, using the Law of Sines and Law of Cosines.

College

College: Applied Trigonometry

Apply triangle-solving methods in precalculus, physics, and engineering-style problems.

By Assignment Type

Get Instant Help with Triangle Assignments

Whether it's a right triangle or an oblique one, get the correct method and a full explanation every time.

Problem Sets

Quizzes & Tests

Word Problems

Worksheets

Get Triangle Homework Help Anytime, Anywhere

Ready to know exactly which formula to reach for? Use our free Triangle Solver today.

Start Solving Triangles Now
Stay In Math

More Free Math Solvers

Expert Level Academic Help

Need Help Beyond Triangles?

Our AI is fine-tuned for the unique logic of each discipline. Select a subject below to calibrate the solver for specific terminology and academic standards.

Used by students globally for standardized exam preparation and daily assignments.

FAQ

Frequently Asked Questions

Yes. Enter what you know about your triangle above and get a full step-by-step solution for the missing side, angle, or area.

Yes, it uses the Law of Sines and Law of Cosines to solve any triangle, not just right triangles.

Yes, when only the three side lengths are known, it uses Heron's formula and shows the calculation.

Yes. Tap the upload or camera icon, take a photo of your worksheet or diagram, and the AI will read and solve it, no sign up required.

Yes, for middle school it focuses on finding a missing side of a right triangle with simple explanations.

Yes, it applies SSS, SAS, ASA, and AA criteria and explains which one fits the given information.

Yes, there is no cost and no account needed.

Yes, it recognizes 30-60-90 and 45-45-90 triangles and applies their fixed side-length ratios directly.

The solver figures this out for you based on which sides and angles you already know, and explains why that method fits.