Question

trying it out #4: same as #1. this time use a subtraction method to find the area. the area of the whole rectangle (blue) - the area of the missing piece (red) area sq units my math

Explanation:

Step1: Calculate area of whole rectangle

The whole rectangle has length $l = 11$ and width $w=10$. Using the formula for the area of a rectangle $A = l\times w$, we have $A_{whole}=11\times10 = 110$ square - units.

Step2: Calculate area of missing piece

The missing (red - colored) piece is also a rectangle with length $l = 11 - 4=7$ and width $w = 4$. Using the area formula $A = l\times w$, we get $A_{missing}=7\times4 = 28$ square - units.

Step3: Calculate area of the figure

To find the area of the figure, we subtract the area of the missing piece from the area of the whole rectangle. So $A=A_{whole}-A_{missing}=110 - 28=82$ square - units.

Answer:

82