Shaded area
Initial explanation
We want to find the shaded area. We could do this taking several ways. This time we are going to find the big area using two rectangles:
We will find the area for both and then add them:
area 1 + area 2
But inside of it there is an unshaded square.
That is why, we are going to substract the unshaded area:
This is
area 1 + area 2 - area 3
It will give us the shaded area.
Area 1
We know that the area of a rectangle is given by
side 1 x side 2
In this case:
side 1 = 5cm
and
side 2 = 3 cm
Then, the area of the rectangle 1 is:
side 1 x side 2 = 5cm x 3 cm
= 15 cm²
area 1 = 15 cm²
Area 2
We use
side 1 x side 2
For the second rectangle, we have: