9514 1404 393
Answer:
1. 42 square feet
2. 3192 square cm
Explanation:
In general, the shaded area is the area of the bounding geometry less the unshaded area inside that boundary. In each case here, the bounding geometry is a rectangle, and the unshaded area is some portion of a circle. The rectangle and circle area formulas are used.
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1. shaded area = square area - circle area
shaded area = (14 ft)² = π(7 ft)² = (196 -49π) ft²
We will use 22/7 for pi, so the shaded area is ...
(196 -49(22/7)) ft² = (196 -154) ft²
shaded area = 42 ft²
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2. Here, the bounding box is a rectangle, and we only need to subtract a semicircle.
shaded area = (50 cm)(70 cm) -1/2(22/7)(14 cm)² = 3500 cm² -308 cm²
shaded area = 3192 cm²