Find the Length of an Arc

Do you need an arc?

I Noah guy.....

Apart from the ark that Noah built, there is another kind.

As you can see from the diagram below, an arc is a part of the circumference of a circle.

Probably the only time you will need to calculate the length of an arc is in maths lessons.  (Unless Noah offers you a job)

Maths is a little bit like building Noah's ark.

It is easy if you read the instructions carefully. 

Instructions in maths come in the form of a formula.

Being part of a circle, pi   is involved of course.

Circumference of a circle is π  x diameter  (πd)

Since an arc is part of the circumference, it makes sense to use this as part of our calculation:

Length of an arc = angle ÷ 360 x π x diameter

Generally in maths questions, you're given the radius of the circle - you could double the radius to get the diameter or the formula applied could be:

Length of an arc = angle ÷ 360 x 2 x π x radius          

Remember you can use the π button on your calculator or use the values 3.14 or 3.142 in your calculations.