if leg a is the missing side, then transform the equation to the form when a is on one side, and take a square root: a = √(c² - b²)
if leg b is unknown, then. b = √(c² - a²)
for hypotenuse c missing, the formula is. c = √(a² + b²)
use a right triangle calculator :)
or those math apps on yo phone (photomath )