Question

What is the area of number 4?

Answer 1

Answer:

800 cm²

Step-by-step explanation:

Look at the picture.

We have three rectangles. The formula of an area of a rectangle:

$A=lw$

l - length

w - width

Rectangle I:

$A_I=7\cdot20=140\ cm^2$

Rectangle II:

$A_{II}=6\cdot20=120\ cm^2$

Rectangle III:

$A_{III}=18\cdot30=540\ cm^2$

The area of number 4:

$A=A_{I}+A_{II}+A_{III}$

Substitute:

$A=140+120+540=800\ cm^2$