Question

Calculate the area of the blue surface in ${\text{cm}}^2$.

• A. 36

Answer 1

The correct option is A 36
The shaded portion can be split into two rectangles as shown:



The bigger rectangle has an area of:
$A_1=4cm\times 7cm$
$A_1=28c{m}^2$

The smaller rectangle has an area of :
$A_2=4cm\times 2cm$
$A_2=8c{m}^2$

The total area of the shaded portion is the sum of above two areas:
$A=28c{m}^2+8c{m}^2=36c{m}^2$