Question

The area of the shape below is

84 square centimeters.
a
10 cm
6 cm
12 cm
What is the length of a?

Answer 1

D=3

Explanation:

Split this figure into 2 parts. Now you have 2 rectangles. One with sides 6 and 12. Other with sides (10 - 6) =4, and a.

Area of one rectangle is 12 × 6 = 72

Area of 2nd rectangle is 4 × a = 4a.

Since we know the total area of figure is 84

that means

72 + 4a = 84

4a = 84 - 72

4a = 12

a = 12 ÷ 4 = 3

a=3

Answer 2

Its D. 3cm

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