Question

Which expression gives the area of the triangle shown below

Answer 1

The area of triangle is

`A_(triangle)=(1)/(2)\cdot \text{base}\cdot \text{height}.`

From the diagram it is seen that

`\text{ base }=r,\\\text{ height }=x.`

Then

`A_(triangle)=(1)/(2)\cdot r\cdot x.`

Answer: correct choice is D.