Question

2. Hank used a semicircle, a rectangle, and a triangle to form the following composite figure. What is its area in square centimeters? Use 3.14 to approximate.

Answer 1

`Surface\ Area = 179.25cm^2`

Explanation:

Given

See attachment for figure

Required

Determine the surface area

To do this, we calculate the surface area of each individual shape.

For the semicircle.

`Area = (1)/(2)\pi r^2`

Here, the diameter (D) is given

`D = 10cm`

The radius is:

`r = (1)/(2)D`

`r = (1)/(2)*10cm`

`r= 5cm`

So, the area is:

`Area = (1)/(2) * 3.14 * (5cm)^2`

`Area = (1)/(2) * 3.14 * 25cm^2`

`Area = 39.25cm^2`

For the triangle, the area is:

`Area = (1)/(2)bh`

`Area = (1)/(2) * 10cm * 8cm`

`Area = 40cm^2`

For the rectangle

`Area = Length * Width`

`Area = 20cm * 5cm`

`Area = 100cm^2`

So, the surface area is:

`Surface\ Area = 39.25cm^2 + 40cm^2 + 100cm^2`

`Surface\ Area = 179.25cm^2`