Question

the area of a sector of a circle is given by 1/2 (r^2) theta (theta in radians) so that an area element A= 1/2 (r^2)theta calculate the area of the semi circle

Answer 1

the area of a sector of a circle is given by 1/2 (r^2) theta (theta in radians) so that an area element A= 1/2 (r^2)theta calculate the area of the semi circle

A = (1/2)r^2.θ

For a semi-circle the included angle of the sector iis θ = π rads.

Therefore the area is,

A = (1/2)π.r^2