Calculate right triangle online

This function calculates the most important parameters of a right triangle when the lengths of two sides are known. As result, the cathet and hypotenuse, height, perimeter, area, hypotenuse sections and the angles are displayed.

For calculation select the pages you are familiar with in the menu and enter their values. Then click on the 'Calculate' button.

Right triangle  Input Delete Entries length a length b length b length c Decimal places 0 1 2 3 4 6 8 10  Results Cathetus a Cathetus b Hypotenuse c Height h Perimeter P Area A Section p Section q Angle α Angle β

Formulas and description of right-angled triangles

In the case of a right angle, the cathets are the two sides at the right angle. The hypotenuse is the side opposite the right angle. The height is measured from the right angle to the hypotenuse. The hypotenuse sections are the sections of the hypotenuse from the respective corner to the point where the line of height hits the hypotenuse.

Hypotenuse (c)

\(\displaystyle c=\sqrt{a^2+b^2} \)

Cathete (a)

\(\displaystyle a=\sqrt{c^2-b^2} \)

Cathete (b)

\(\displaystyle a=\sqrt{c^2-a^2} \)

Area (A)

\(\displaystyle A = \frac{ a · b}{2} \)    \(\displaystyle A = \frac{ c · h}{2} \)

Perimeter (P)

\(\displaystyle P=a+b+c \)

Height (h)

\(\displaystyle h = \frac{ a · b}{c} \)    \(\displaystyle h=\sqrt{ p · q} \)

Section (p)

\(\displaystyle p= \frac{a^2}{c} \)

Section (q)

\(\displaystyle q = \frac{b^2}{c} \)

Angle (α)

\(\displaystyle α = arcsin \left( \frac{a}{c} \right) \)    \(\displaystyle α = arccos \left( \frac{b}{c} \right) \)

Angle (β)

\(\displaystyle β = arcsin \left( \frac{b}{c} \right) \)    \(\displaystyle β = arccos \left( \frac{a}{c} \right) \)