The legs of a right-angled triangle are 30 and 40. Find the hypotenuse of this triangle.

Given: right-angled triangle ABC;
angle C = 90;
leg AC = 30 centimeters;
leg CB = 40 centimeters.
Find: hypotenuse AB -?
Decision:
Consider a right-angled triangle ABC. By the Pythagorean theorem (the square of the hypotenuse is equal to the sum of the squares of the legs):
AC ^ 2 + BC ^ 2 = AB ^ 2
AB ^ 2 = 30 ^ 2 + 40 ^ 2;
AB ^ 2 = 30 * 30 + 40 * 40;
AB ^ 2 = 900 + 1600;
AB ^ 2 = 2500;
AB = √ 2500
AB = 50 centimeters – the length of the hypotenuse.
Answer: 50 centimeters.