The hypotenuse of a right triangle is 8 centimeters long. One of the legs of the triangle is 7 centimeters. What is the length of the triangle's other leg?

For a right triangle a^2 + b^2 = c^2 where c is the hypotenuse. Substituting the values we know we can rewrite this as

7^2 + b^2 = 8^2

b^2 + 49 = 64

b^2 = 64 - 49

b^2 = 25

Take the square of both sides and you get b = + 5 and - 5. However, since a side cannot have a negative value the answer is 5.

The last leg is 5cm.