A triangle has sides of length 3, 4, and 5. What is the area of the triangle?

This is a right-angled triangle because it satisfies the Pythagorean theorem: $$3^2 + 4^2 = 9 + 16 = 25 = 5^2$$. The area of a right-angled triangle is given by $$\frac{1}{2} \times \text{base} \times \text{height}$$.

Ответ: $$6$$