Answer:
Area of semi-circle =
Perimeter of semi-circle =
where r is the radius
Explanation:
Pi has been used in the construction of arches, bridges, churches and buildings.
Since the bridges and arches are semicircles, Pi helps in determining perimeter of the semicircle which in turn helps in calculating the amount of material required for construction.
Area of semi-circle =
Perimeter of semi-circle =
where r is the radius