Question

Find the correct plugged in formula for each figure.

Answer 1

`Area = 40 ( 84)+ 2 *(294)`

Explanation:

There is only one figure in the attached image and the solution (surface area) is as follows:

The shape can be sub-divided into:

1. Rectangle

Dimension: 40 by 35

2. Rectangle

Dimension: 40 by 28

3. Rectangle

Dimension: 21 by 40

4. 2 triangles

Base: 21 and Height: 28

Calculate area of each and add them up to get the surface area of the figure.

1. Rectangle

Dimension: 40 by 35

`A_1 = 40 * 35`

2. Rectangle

Dimension: 40 by 28

`A_2 = 40 * 28`

3. Rectangle

Dimension: 21 by 40

`A_3 = 40 * 21`

4. 2 triangles

Base: 21 and Height: 28

`A_4 = 2 * (1)/(2) * 21 * 28`

So, the area is:

`Area = A_1 +...+A_4`

`Area = 40 * 35 + 40 * 28 +40 * 21 + 2 * (1)/(2) * 21 * 28`

Factor out 40

`Area = 40 ( 35 + 28 + 21 )+ 2 * (1)/(2) * 21 * 28`

`Area = 40 ( 84)+ 2 * (1)/(2) * 21 * 28`

`Area = 40 ( 84)+ 2 *(294)`