Question

Here is a picture that shows one side of a child's wooden block with a semicircle cut out at the bottom.

The face of an arch-shaped block. The horizontal side of the block is labeled 9 centimeters and the vertical side of the block is labeled 4.5 centimeters. A semi circle with diameter labeled 5 centimeters is removed from the block.
Find the area of the side.

Answer 1

30.7 cm² (nearest tenth)
Explanation:
Area of the wooden block = area of rectangle - area of semi-circle
Area of Rectangle = length × width
Length = 9 cm
Width = 4.5 cm
Area of rectangle = 40.5 cm²
Area of semi-circle = ½(πr²)
Radius (r) = ½ of diameter = ½*5 = 2.5 cm
π = 3.14
Area of semi-circle = ½(3.14*2.5²)
Area of semi-circle = 9.8125 cm²