Right Triangle Calculator

Right Triangle Calculator is the fastest, most accurate way to solve any triangle — and actually understand how. Enter the values you know and instantly get every missing side, angle, area and perimeter, complete with a clear step-by-step solution. No guessing and no messy formulas by hand — just tap, type and solve.

From a simple right triangle to a full oblique triangle, this all-in-one triangle solver and trigonometry calculator handles them all. Whether you are a student working through geometry homework, a teacher preparing a lesson, or a carpenter, engineer, machinist or DIY builder measuring on the job, it turns tricky trigonometry into a few quick taps.

► SOLVE ANY TRIANGLE

• Right triangle solver powered by the Pythagorean theorem (a² + b² = c²)
• Oblique, scalene, isosceles, equilateral and obtuse triangles
• Enter any valid 2–3 values — SSS, SAS, ASA or AAS — and get everything else
• Handles the tricky ambiguous case (SSA) and shows every possible triangle
• Instantly finds sides, angles, hypotenuse, area, perimeter and all three heights

► SEE EVERY STEP, NOT JUST THE ANSWER

• Clear, step-by-step solutions using Pythagoras, the sine rule and the cosine rule
• Understand the exact formula and working behind every single result
• Perfect for learning, revising and checking your homework with confidence

► BUILT FOR REAL, EVERYDAY USE

• Tap any side or angle right on the triangle diagram and start typing
• Fast, purpose-built keypad — no fiddly system keyboard getting in the way
• Live guidance shows exactly how many values you still need to enter
• Switch instantly between degrees, radians and DMS (degrees-minutes-seconds)
• Choose your own decimal precision, up to 10 places — never any forced rounding
• Metric and imperial units supported
• Full calculation history, so you can revisit earlier answers any time

► POWERFUL GEOMETRY TOOLS

• Circumcircle and incircle diameter calculators
• Regular polygon tools for triangle, square, pentagon, hexagon and octagon
• Ideal for machining, PCD (pitch circle diameter) and workshop layout work

► HANDY EXTRAS

• Similarity and Thales mode — find the height of a tree, pole or building from its shadow
• Solve from a photo — snap a printed problem, read off the values and get your answer
• Automatic right-angle detection with clear, colour-coded diagrams
• Save, review and share your results in seconds

► LEARN AND COMPETE

• Fun practice quizzes to sharpen your geometry and trigonometry skills
• Instant feedback with a clear explanation for every question
• On-device leaderboard with Diamond, Gold and Silver tiers to keep you motivated

► PERFECT FOR

• Students — geometry and trigonometry homework, exam revision and quick checks
• Teachers — clean visuals and worked solutions for the classroom
• Carpenters, builders and DIY — roof pitches, rafters, ramps and angles
• Engineers, machinists and surveyors — precise, reliable calculations on site

► WHY YOU WILL LOVE IT

• Works completely offline — no internet connection required, wherever you are
• Clean, modern design with beautiful dark and light modes
• Simple, honest and genuinely easy to use — solve in seconds
• Fast and accurate results you can trust, every single time

Math and measuring should be simple. Stop struggling with hand calculations and half-remembered formulas — let Right Triangle Calculator do the hard part while showing you exactly how it got there, so you learn as you go.

Download Right Triangle Calculator today and get fast, accurate triangle and trigonometry answers — with the full working shown — anytime, anywhere.