SOLUTION: 1. The area of a circle is 28 sq meters. What is the circumference? 2. A cylinder drum has a diameter of 3 yards and a volume of 65 cubic yards. What is height of drum?

Algebra ->  Surface-area -> SOLUTION: 1. The area of a circle is 28 sq meters. What is the circumference? 2. A cylinder drum has a diameter of 3 yards and a volume of 65 cubic yards. What is height of drum?      Log On


   

Question 334899: 1. The area of a circle is 28 sq meters. What is the circumference?
2. A cylinder drum has a diameter of 3 yards and a volume of 65 cubic yards. What is height of drum?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
1. The area of a circle is 28 sq meters. What is the circumference?
Find r from the area:
pi%2Ar%5E2 = 28
r = sqrt%2828%2Fpi%29
;
Find the circumference
C = 2%2Api%2Ar
Replace r withsqrt%2828%2Fpi%29
C = 2%2Api%2Asqrt%2828%2Fpi%29
enter into a calc
C = 18.758 m
:
:
2. A cylinder drum has a diameter of 3 yards and a volume of 65 cubic yards.
What is height of drum
Vol of a cylinder
pi%2Ar%5E2%2Ah = V
Find the radius: r = 3/2 = 1.5 yds
pi%2A1.5%5E2%2Ah = 65
pi%2A2.25%2Ah = 65
h = 65%2F%282.25%2Api%29
using a calc
h = 9.1956 yds is the height
:
;
Check by finding the vol with this height
V = pi%2A1.5%5E2%2A9.1956
V = 65.00