(a)

Observe the graph :

The equations are and .

The height of the triangle is equal to the value of the .

Susbtitute in .

.

The height of the triangle is .

The base of the triangle is .

The area of the triangle is .

.

The height of the triangle is , width is and area is .

(b)

The integral is .

Find the area of the triangle.

.

.

Therefore, the area of the triangle is  .

(a) The height of the triangle is , width is and area is .

(b) The area of the triangle is  .