We are given a rectangle with a semi-circle cut out. We need to find the area of the remaining region. The rectangle has length 22 cm and height 8 cm. The semi-circle's diameter spans the entire width of the rectangle except for two segments, each 4 cm in length, so the diameter of the semi-circle is $22 - 4 - 4 = 14$ cm. Thus, the radius is $14/2 = 7$ cm.

GeometryArea CalculationRectangleSemi-circleGeometric ShapesSubtractionApproximation of Pi
2025/4/29

1. Problem Description

We are given a rectangle with a semi-circle cut out. We need to find the area of the remaining region. The rectangle has length 22 cm and height 8 cm. The semi-circle's diameter spans the entire width of the rectangle except for two segments, each 4 cm in length, so the diameter of the semi-circle is 2244=1422 - 4 - 4 = 14 cm. Thus, the radius is 14/2=714/2 = 7 cm.

2. Solution Steps

First, calculate the area of the rectangle.
Area of rectangle = length * height
Arectangle=22×8=176A_{rectangle} = 22 \times 8 = 176 cm2^2
Next, calculate the area of the semi-circle.
The area of a circle is given by A=πr2A = \pi r^2. The area of a semi-circle is half of the area of a circle.
Asemicircle=12πr2A_{semi-circle} = \frac{1}{2} \pi r^2
Asemicircle=12π(72)=12π(49)=49π2A_{semi-circle} = \frac{1}{2} \pi (7^2) = \frac{1}{2} \pi (49) = \frac{49\pi}{2}
We can approximate π\pi as 227\frac{22}{7} to get a numerical value.
Asemicircle=492×227=71×111=77A_{semi-circle} = \frac{49}{2} \times \frac{22}{7} = \frac{7}{1} \times \frac{11}{1} = 77 cm2^2
Now, subtract the area of the semi-circle from the area of the rectangle to find the area of the remaining part.
Area of remaining part = Area of rectangle - Area of semi-circle
Aremaining=17677=99A_{remaining} = 176 - 77 = 99 cm2^2

3. Final Answer

The area of the remaining part is 99 cm2^2.
Final Answer: B. 99 cm2^2

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