Question

1. A circle has a radius of 12 in. Find:

The diameter of the circle.

The circumference of the circle.

The area of the circle.

2. A circle has a radius of 4.4 cm. Find:

The diameter of the circle.

The circumference of the circle.

The area of the circle.

3. A circle has a diameter of 60 m. Find:

The radius of the circle.

The circumference of the circle.

The area of the circle.

4. A circle has a diameter of 1.8 km. Find:

The radius of the circle.

The circumference of the circle.

The area of the circle.

Answer 1

Answers (I did not round numbers, not sure if you needed that and to what decimal?
1. Given radius (R) = 12
Diameter = 2R = 24
Circumference = 2πR
= 75.398223686155
Area = πR2
= 452.38934211693

2. Given radius (R) = 4.4
Diameter = 2R = 8.8
Circumference = 2πR
= 27.64601535159
Area = πR2
= 60.821233773498

3. Given diameter (D) = 60

Radius = 1/2 D
= 30
Circumference = πD
= 188.49555921539
Area =
pi (D/2) ^2
= 2827.4333882308

4. Given diameter (D) = 1.8

Radius =
D/2
= 0.9
Circumference = πD
= 5.6548667764616
Area =
π( D/2 ) ^2
= 2.5446900494077

Answer 2

1.

a.) 24in

b.)75.36in

c.)452.16in

Explanation:

1a. The radius is half of the diameter, so all you have to do is add 12 + 12 which is 24.

1b. the circumfrence of a circle is C (Circumfrence)=
`2\pi r` so replace radius for 12 and then do 3.14(pi) x 2 which will get you 6.28 times 6.28 by 12 and you will get 75.36.

1c. Area=
`\pi r^(2)` so first do the radius by the second power, or
`r * r`, susitute r for 12 and you will get 144, times 144 by pi and you will get 452.16in

Sorry I could not answer every question but hope this helps!