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Merlynmercado1901go
Answered

Activity 3
Solve for the circumference of a circle. Write the letter of the correct answer.
1. A circle has a radius of 5 cm. What is its circumference?
a. 14.37 cm b. 31.4 cm c. 15.7 cm
d. 41.3 cm
2. A circle has a radius of 9 m. Find its circumference,
a. 56.52 m b. 43.52 m c. 28.26 m
d. 16.25 m
3. What is the circumference of a circle whose radius is 3 in?
a, 18.84 in b. 12.84 in c. 9.42 in
d. 6.28 in
4. The diameter of a circle is 15 ft. What is its circumference?
a. 15.7 ft
b. 28.1 ft
C, 47.1 ft d. 56.7 ft
5. Find the circumference of a circle whose diameter is 12 cm.
a, 9.76 cm
b. 18.84 cm c. 27.85 cm
d. 37.68 cm​

Sagot :

Rktmobilezgo

Circumference of Circle

C = 2πr or C = πd

where

C = Circumference

π = 3.14

r = radius = length given is radius *

d = diameter = length given is diameter *

TIP: No need to memorize 2 formulas.

Use C = 2πr as default since a lot of other formulas use radius (r) instead of diameter (d).

Just remember relationship of diameter (d) and radius (r).

d = 2r or r = ½d

So let's solve some numbers,

#1.

solve C, when r = 5cm

C = 2πr

C = 2(3.14)(5)

C = 31.4 cm

#4

solve C, when d = 15ft

you can use C = πd

or if you want to stick with remembering just,

C = 2πr

then don't forget to convert diameter (d) to radius (r)

r = d/2 = 15/2 = 7.5 ft

now solve for C,

C = 2πr

C = 2(3.14)(7.5)

C = 47.1 ft

Now follow the same process to solve for #2, #3 and #5.

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