1981 AHSME Problems/Problem 11
The three sides of a right triangle have integral lengths which form an arithmetic progression. One of the sides could have length
Let the three sides be and Because of the Pythagorean Theorem, This can be simplified to
So, is a multiple of and the triangle has sides We check the answer choices for anything divisible by 3, 4, or 5. The only one that works is 81, which is divisible by 3.
The answer is
-edited by coolmath34