Question

A diagram of a concrete patio is shown, where each small square represents one square meter. Find the total area of the concrete patio.

Answer 1

C

Explanation:

The red bordered area is the patio. We need to find its area.

We will consider

If this was a square, full red square. Then we find the area of the square.

After that, we will subtract the white part that is not there to create the patio shape.

Hence,

Area of Patio = Area of Square - Area of White Portion

So,

Area of Square is Side * Side

If we look at the coordinates, x goes from 5 to 15, so side is 15 - 5 = 10

also, y goes from 5 to 15, so same, that is 10

Area of Square = 10 * 10 = 100

Now, the small white portion is also a square with length 5 (looking at coordinates),

So,

Area of White Portion = 5 * 5 = 25

Hence,

Area of Patio = 100 - 25 = 75 sq. meters

Correct answer is C