Page 13 - C:\Users\ASUS\Documents\Flip PDF Corporate Edition\MINI BOOK_DWI ANTIKA BR NASUTION_MESP2019\

C. Circumference and Area of Circle

- Circumference of Circle

What is the formula for finding the circumference of a circle? Well, let's see how
to calculate the circumference of a circle through the problems below.

.................................................................................................................................
Tomorrow is Mom and Dad's wedding anniversary. Nina made a round cake as
shown in the picture above with a diameter of 28 cm. The first part of the cake
that is decorated is the top of the cake, which is circular in shape with cream.
You can calculate the circumference of the circle by measuring the length of the
top edge of the cake.

Based on the problems above, what information do you get? Form groups of
3-4 people. Record your observations in your workbook. Then, what is meant
by the circumference of a circle?

Based on the problem above, we know that the circumference of a circle is the
length of the curved line of a circle. In calculating the circumference of a circle
is not difficult. You can use two ways to calculate the circumference of a circle,
namely if you know the radius (r) or if you know the diameter (d) as follows:

K = 2 π r (if known radius)
K = π d (if known diameter)
With
K = circumference circle
r = radius
d = diameter

by

atau 3,14

8