Answer: 120 square cm
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Work Shown:
Let,
- A = area of unshaded rectangle (the 6 by 10 rectangle)
- B = area of the unshaded triangle (that has the "8 cm" inside it)
- C = area of parallelogram
- D = shaded area = C - (A+B) = C - A - B
We can see that A = 60 since the rectangle has base 10 and height 6, so 10*6 = 60.
The upper horizontal part of the parallelogram is 10+8 = 18 cm long. This means the bottom horizontal part of the parallelogram is the same length. The bottom portion shows 9 cm until we reach the triangle. This means that 18-9 = 9 cm is the base of the unshaded triangle (that has the "8 cm" inside it).
That triangle has area of 0.5*base*height = 0.5*9*8 = 36 square cm. So B = 36
The parallelogram has base 18 cm and height 12 cm, so it has area of 18*12 = 216. This means C = 216
We can then finally compute the value of D
D = C - A - B
D = 216 - 60 - 36
D = 120 square cm