This all-in-one online Right Triangle Calculator helps to calculate the missing parameters of a right triangle provided any two of the triangle sides or any side and any acute angle are known.
Right triangle formulas
A right triangle (or right-angled triangle) is a triangle in which one angle is a right angle (a 90° angle). In a right triangle, the side that is opposite the right angle is the longest side of the triangle, and is called the hypotenuse. The sides adjacent to the right angle are called legs. The sides of a right triangle are connected by the following equation (Pythagorean theorem):
$$a^{2}+b^{2}=c^{2},$$
where \(c\) represents the length of the hypotenuse and \(a\) and \(b\) the lengths of the triangle’s other two sides.
The relation between the sides and angles of a right triangle is the basis for trigonometry. For instance, the ratio of any leg to the hypotenuse defines the sine function:
$${\displaystyle \sin{B} ={\frac {b}{c}}={\frac {\mathrm {opposite~to~B} }{\mathrm {hypotenuse} }}},$$
$${\displaystyle \sin{C} ={\frac {a}{c}}={\frac {\mathrm {opposite~to~C} }{\mathrm {hypotenuse} }}}.$$
The above formulas are used in our right triangle calculator. When only sides are specified you actually have a right triangle angle calculator.
Related calculators
To calculate parameters of an arbitrary triangle check out our Triangle Calculator.