A triangle has sides of length 15, 20, and 25. What is the area of the triangle?

This is a right-angled triangle because $$15^2 + 20^2 = 225 + 400 = 625 = 25^2$$. The area of a right-angled triangle is $$\frac{1}{2} \times \text{base} \times \text{height}$$.

Ответ: $$150$$