The lengths of two sides of ABC are 15 and 20, and the triangle area is 150. What is the perimeter of ABC?
Thank you :)
At first glance, it seems like Heron's formula is needed, but notice that \(\frac{15\cdot20}{2} = 150\). That means 15 and 20 are the length of the legs of a right triangle.
The hypotenuse of that triangle is \(\sqrt{15^2+20^2}=25\), using the Pythagorean theorem.
The perimeter of ABC is therefore equal to \(15+20+25=\boxed{60}\)