Question 545329
Use the Pythagorean theorem: 
For any right triangle, the square of the hypotenuse (the longest side) is equal to the sum of the squares of the two legs.
{{{c^2 = a^2+b^2}}} c = the hypotenuse and a and b are the two legs.
In this problem, c = 17, a = 8 and b = 15.
{{{17^2 = 289}}}
{{{8^2+15^2 = 64+225 = 289}}}
So the three given sides make a right triangle.