Question

how can you find a lateral surface area and a total surface area?The numbers below are:20 8 13 728 528 840 56 66 42

Answer 1

We have that the lateral surface area is given by the parts of the figure that are not at the top or the bottom of the figure. Then, we have that the lateral surface area is given by:

`2\cdot(20\cdot13)+2\cdot(8\cdot13)=520+208=728`

And we can take common factors as follows:

`2\cdot13\cdot(20+8)=2\cdot13\cdot28=13\cdot2\cdot28=13\cdot56=728`

Then, we have that the Lateral Surface Area is:

13 x 56 (which is equal to 728 sq. inches)

Then, we need to add the area of the top and the bottom of the figure:

`20\cdot8+20\cdot8=2\cdot(20\cdot8)=2\cdot160=320`

Then, we have that the total surface area is:

728 + 2 * (20x8)

The total area is then 728 + 320 = 1048 square inches.

In the question above, we can write (second line):