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Lesson 5: Estimating the Area of a Circle



 1. 

Estimate the area of a circle with each radius.

r = 3 cm
a.
20 cm2
b.
30 cm2
c.
40 cm2
d.
50 cm2
 

 2. 

r = 8 m
a.
100 m2
b.
200 m2
c.
300 m2
d.
400 m2
 

 3. 

r = 4.5 mm
a.
60.0 mm2
b.
70.0 mm2
c.
80.0 mm2
d.
90.0 mm2
 

 4. 

r = 16.7 cm
a.
600.0 cm2
b.
750.0 cm2
c.
850.0 cm2
d.
1000.0 cm2
 

 5. 

Estimate the area of a circle with each diameter.

d = 10 m
a.
60 m2
b.
70 m2
c.
80 m2
d.
300 m2
 

 6. 

d = 14 mm
a.
100 mm2
b.
150 mm2
c.
200 mm2
d.
250 mm2
 

 7. 

d = 17.5 mm
a.
100.0 mm2
b.
250.0 mm2
c.
500.0 mm2
d.
1000.0 mm2
 

 8. 

d = 0.5 m
a.
0.2 m2
b.
1 m2
c.
2 m2
d.
3 m2
 

 9. 

Garrett is covering a wooden circular surface with material. If the diameter of the circle is 7 m, about how much material will he need?
a.
15 m2
b.
40 m2
c.
100 m2
d.
200 m2
 

 10. 

A clock has a minute hand that is 8 cm long.  Approximately what is the area of the clock face?
a.
200 cm2
b.
500 cm2
c.
1000 cm2
d.
2000 cm2
 



 
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