Question

Find the circumference and area of a circle with a radius 9 cm.

Answer 1

Your answer would be 56.52 cm (18π) for the circumference, and 254.34 cm² (81π) for the area.

The formula for the circumference of a circle is 2πr. In this case, we know that the radius is 9, so substituting it in, you get 2 * 9 * π. Solving this, we get 18π as our circumference. Your question states to use 3.14 as π, so the final step is to multiply 18 by 3.14. 18 * 3.14 = 56.52. The unit in this case would just be cm, as we are looking at circumference, or length.

The formula for the area of a circle is πr². Again, we know r = 9, so just substitute it in the equation, to get π9², which can be solved to equal 81π. Then, using 3.14 as π, we get 81 * 3.14 = 254.34 as our final answer. The unit in this case would be cm², as this is concerning area.

Hope this helps!

Answer 2

Answer:

C =56.52 cm

C =56.52 cm

C =56.52 cm

A =254.34 cm^2

Step-by-step explanation:

To find the circumference of a circle, we use

C = 2 * pi *r

where pi is approximated by 3.14 and r is 9

C = 2 * 3.14 *9

C =56.52 cm

To find the area of a circle, we use

A = pi *r^2

where pi is approximated by 3.14 and r is 9

A = 3.14 *9^2

A =254.34 cm^2