$\"\"$

(a)

The graph is in the form of triangle.

Observe the graph,

Base $\"\"$ units.

Height $\"\"$ units.

Use pre-calculus concept to find the area of the region.

Area of the triangle is $\"\"$ .

$\"\"$

Area of the region is $\"\"$ square units.

$\"\"$

(b)

Observe the graph,

Base $\"\"$ units.

Use Calculus concept to find the area of the region.

Height is varies from $\"\"$ to $\"\"$ units.

Therefore average height $\"\"$ .

Area of the region is $\"\"$ .

$\"\"$

Area of the region is $\"\"$ square units.

(a) Pre-calculus : Area of the region is $\"\"$ square units.

(b) Calculus : Area of the region is $\"\"$ square units.