How to Find the Perimeter of a Semi Circle

How to Find the Perimeter of a Semi Circle
••• katiko-dp/iStock/GettyImages

The continuous closed line that makes the boundary of a two-dimensional shape is known as the perimeter. It’s easy to work out the perimeter of a shape with straight edges, such as a square, because you simply add the lengths of each edge together. A different formula is required to work out the perimeter of a semi circle (a circle cut in half), because it consists of a curved edge as well as a straight edge. That formula is

P = \frac{1}{2} πd + d

where ​d​ is the diameter of the semi circle.

    Apply the number pi (π) to the formula

    P = \frac{1}{2} πd + d

    Pi is a circle's circumference divided by its diameter and is always the same value, 3.14.

    To find the perimeter of a semi circle, you have to know the diameter (the length of its straight edge). For example, if the diameter of your semi circle is 12 centimeters, the formula becomes

    P = \frac{1}{2} ×(3.14×12) + 12

    Work out

    3.14 × 12 = 37.68

    Then work out

    37.68 ÷ 2 = 18.84

    You now have the perimeter of the curved edge of the semi circle. But a semi circle also has a straight edge, which is why you have to add the length of the diameter to calculate the whole perimeter. In this case, work out

    18.84 + 12 = 30.84

    The perimeter of your semi circle is 30.84 centimeters.

Related Articles

What is Perimeter?
How to Calculate Perimeter and Area Ratio
How to Find the Circumference of an Octagon
How to Calculate the Area of a Curved Surface
How to Figure the Cubic Yards in a Circle
How to Convert Diameter to Square Centimeters
How to Find the Radius of a Cone
How to Find the Volume of a Semicircle
How to Calculate the Perimeter of Quadrilaterals
How to Find the Volume of a Sphere in Terms of Pi
How to Find the Cross Sectional Area of a Pipe
How to Calculate a 3D Perimeter
How to Calculate the Area of an Oval
How to Calculate Round Area to Square Feet
How to Calculate Cubic Feet of a Cylinder
How to Find Radius From Diameter
How to Calculate the Volume and Circumference of a...
How to Calculate Diameter With Length & Width Only
How to Calculate a Circular Area
How to Convert Square Dimensions to Round

Dont Go!

We Have More Great Sciencing Articles!