Circumferences and Areas of Circles
;ive your answers exactly, in terms of
J r
= 10.5 cm, find
3. If C
=
17,
N'AME
and rounded to the nearest tenth.
C.
9.6n cm, find d.
~.
If C
=
25ncm, find r.
~h
If d
=
12 Cll1, find C.
5. What is the circumference of a circle whose radius is
6. What is the diameter of
_
30 cm?
a: circle whose circumference is 24n cm?
7. In order to increase the circumference of a circle from 16n cm to
20n cm, by how much must the diameter increase?
.
8. If d
=
9.6 em, find C.
9. If r
== 8.1
cm, find
C.
10.
He
= D2 em, find d and r.
"'----­
11. A dinner plate fits snuggly in a square box
with perimeter 48 inches.
What is the circumference· of the plate?
12. Four saucers are part of the same set as the dinner plate in Exercise
i l.
Each has a circumference of 15.7 inches. Will they fit, side by side, in
the same square box? If so, how many inches will there be between the
saucers fat padding?
For Exercises 13-15, find the exact area of the shaded region.
13.
14.
15.
1
JO
j
'-....--.
1
JO
j