Answer:
just for (a.) 126cm²
Step-by-step explanation:
The idea is that;
[Total area which is area of rectangle] - [Total area of circle since the semicircles make a circle] = Shaded region
π= 3/1/7
Area of rectangle= 20 × 14 = 280
Area of circle= the diameter of the circle is 14, diameter=2radius
thus, r=7
Area of circle= πr²
(3/1/7)×7² = 154
hence, 280-154= 126cm²
