The circle The perimeter of a semicircle Remember that the perimeter is the distance round the outside.

A semicircle has two edges. One is half of a circumference and the other is a diameter.

Remember this is the circumference of the whole circle, so now we need to half this answer.

Total perimeter

Area of a circle For any circle with radius, r, the area, A, is found using the formula:

The area of a semicircle A semicircle is just half of a circle. To find the area of a semicircle we calculate the area of the whole circle and then half the answer.

Area of semicircle

The area of a combined shape This shape is made up of a rectangle and a semicircle.

To find the total area we just find the area of each part and add them together.

Area of the rectangle = length x breadth