How to work out the perimeter of a semi-circle, including formula and examples.. The perimeter of a semicircle can be worked out by applying the formula P = (Pi*d/2) + d. This is because a semicicle has two sides; a curved edge and the diameter. Pi*d/2 gives the length of the arc and then you have to make sure you add the diameter back on. Many students forget to add the diameter back on to the final answer.
So in the example in the video, you need to calculate the perimeter of a semicircle which has a diameter of 12cm. So substitute d = 12 into P = (Pi*d/2) + d. This gives P = (Pi*12/2) + 12 = 30.8cm. Make sure that the diameter is substituted into this formula and not the radius.
Tags: How to work out the perimeter of a semi-circle, including formula and examples., math, maths, perimeter of a semicircle, semicircle perimeter, perimeter of a semi-circle, semicircle perimeter formula, perimeter, semicircles, geometry, shapes, shapes semicircle