Short answer = false
Remark
If it is a right triangle, it will obey the Pythagorean Equation. a^2 + b^2 = c^2. Let's see if it does.
Equation
a^2 + b^2= c^2
c must be the longest line. (Hypotenuse)
Givens
a = 24
b = 17
c = 40
Sub and Solve
a^2 + b^2 = c^2
17^2 + 24^2 = c^2 [We'll see if this comes out to 40]
289 + 576 = c^2
865 = c^2 which is no where near what 40^2 equals. 40^2 = 1600
Short answer False
Square root of 865 = (865)^1/2 = 29.4