Alright, so we'll use the Pythagorean Theorem for this one.
⇒ a²+b²=c²
The hypotenuse of a triangle is represented by c² and we're given the values for a and b. For this triangle, we'll make 15 = a and 20 = b. Plug this into the equation and we'll have (15)² + (20)² = c ². This gives us 625 = c². Solve for c by square rooting both sides of the equation. √(625) = c. We now know that c = 25. To take the perimeter, we add a + b + c ⇒ (15) + (20) + (25) = Perimeter.
-Hope this helps!
