Finding Circumference
Name: _____________________________________ Hour: _____
Draw a line to match each mathematical term to its description. The first one is done for you.
1) Radius
the distance from one side of the circle to the other
2) Circumference
the distance from the edge of a circle to its center
3) Diameter
the amount of space the circle takes up ( πr2 )
4) Center
the middle of the circle
5) Area
the distance around the circle ( C = 2πr or πd )
Instructional Video: http://www.youtube.com/watch?v=1XFkAZW-rWg
Find the circumference
16 cm
IMPORTANT: In the video they gave you two answers for the circumference, the exact circumference (16π cm)
and the approximate circumference ( 50.24 cm). I would like you to show both numbers as you complete the
problems below.
For each problem find both the exact and the approximate circumference. SHOW WORK!!!
6)
7)
9 cm
4 cm
C = 2πr
exact: _________
2 • (3.14) • r
approx: _________
C = 2πr
exact: _________
2 • (3.14) • r
approx: _________
For each problem find both the exact and the approximate circumference. SHOW WORK!!!
8)
9)
10 cm
6 cm
exact: _________
approx: _________
10)
exact: _________
11)
7 cm
6 cm
exact: _________
12) diameter:
approx: _________
22 in
exact: _________
14) radius:
approx: _________
approx: _________
13 in
exact: _________
exact: _________
13) diameter:
approx: _________
9 in
exact: _________
15) radius:
approx: _________
approx: _________
1 in
exact: _________
approx: _________