First, we have to find the area of the semicircle :
Area of a semicircle =( π radius^2)/2
Replacing with the values given:
A (semicircle) = (3.14 x 7 ^2 ) /2 = 76.93 cm2
Then, find the area of the triangle:
the triangle is formed by 2 right triangles:
Area of a right triangle = 1/2 x base x height
base = 7cm
height =7cm
Replacing with the values:
A (right triangle) = 1/2 x 7 x7 = 24.5 cm2
Since there are 2 right triangles:
Total triangle area = 24.5+24.5 = 49 cm2
Finally, we have to subtract the total area of the triangle to the area of the semicircle:
76.93-49= 27.93 cm2