Science calculator

Right-triangle trigonometry.

This trigonometry calculator solves a right-angled triangle from any two known values. Enter two sides, or one side and the acute angle θ, then leave the other boxes blank. It calculates the remaining sides and angle using SOHCAHTOA and Pythagoras — useful for GCSE maths revision and practical geometry.

Opposite side a

Adjacent side b

Hypotenuse c

Acute angle θ

Right triangle

—

enter any two values

Opposite side a: —
Adjacent side b: —
Hypotenuse c: —
Acute angle θ: —

Display precision

a^{2} + b^{2} = c^{2}

\sin θ = \frac{a}{c}, \cos θ = \frac{b}{c}, \tan θ = \frac{a}{b}

a opposite side · b adjacent side · c hypotenuse · θ acute angle between b and c

Assumptions

The triangle is right-angled, with the 90° angle between sides a and b.
θ is the acute angle between the adjacent side b and hypotenuse c; side a is opposite θ.
Every side length is positive and the hypotenuse is longer than either other side.
Lengths are converted to metres internally, so the two entered sides may use different units.

How it works

Pythagoras links all three sides of a right-angled triangle: a² + b² = c². Knowing any two sides therefore determines the third.

SOHCAHTOA gives the sine, cosine and tangent ratios for θ. If two sides are known, the inverse trigonometric function finds the angle. If one side and θ are known, the same ratios find both missing sides.

Enter exactly two known values and leave the other boxes blank. Results use up to three significant figures by default (adjustable above), without padding trailing zeroes; calculation uses full browser number precision before display rounding.

Free
No ads
No tracking
No account
Works offline once loaded

From the maker of Ans — a scientific calculator you can own. Same idea: a proper instrument, nothing in the way.