One of the legs of a right-angled triangle = 24 cm, and the other 6 cm smaller. Find the hypotenuse.

A rectangular triangle is a triangle in which one of the corners is a straight line (equal to 90º).
In order to calculate the hypotenuse of a right-angled triangle, you need to apply the Pythagorean theorem, according to which the square of the hypotenuse is equal to the sum of the squares of the legs:
AB2 = BC2 + AC2.
Since the length of the AC leg is 6 cm less than the BC leg, then:
AC = BC – 6;
AC = 24 – 6 = 18 cm;
AB2 = 242 – 182 = 576 – 324 = 252;
AB = √252 ≈ 15.9 cm.
Answer: the length of the hypotenuse AB is 15.9 cm.