Question

6.

Find the area of the shaded region. All angles are right angles. Show your reasoning.
35
10
15
10
30
10
15
10
60

Answer 1

1400 square units

Explanation:

The area can be computed by subtracting the areas of the white rectangles at three corners from the overall 60×30 rectangle.

The upper left corner white space is 10×10 = 100 square units.

The upper right and lower left white spaces are 15×10 = 150 square units each.

Then the shaded area is ...

60×30 -100 -2(150) = 1800 -100 -300 = 1400 . . . square units

_____

Alternate solution

You can extend each of the horizontal edges across the figure to divide it into three rectangles. From the top down, these have dimensions and areas of ...

35×10 +60×10 +45×10 = 10(35+60+45) = 10(140) = 1400 . . . square units

__

Area of a rectangle is the product of length and width.