geometry ... the surface area of a right circular cylindar whose radius is 5 inches and height is 12 inches is givien approximatly by 2 * 3.1416 * 5 squared * 12. evaluate this expression rounded to two decimal places
2007-08-26 19:47:20 · 5 answers · asked by Stephani K 1 in Science & Mathematics ➔ Mathematics
The formula for the surface area of a cylinder:
2*pi*r*h is the cruved surface area
2*pi*r^2 is the area of circles at the top and bottom of the cylinder
2*pi.r^2 + 2*pi*r*h
= 2*pi*r(r + h)
= 2*3.1416*5*(5+12)
= 534.07 inches^2
2007-08-26 20:38:30 · answer #1 · answered by gudspeling 7 · 0⤊ 0⤋
Hi,
You are trying to calculate the surface area of a cylinder. The radius is 5 inches and the height is 12 inches.
The surface area of a cylinder is caculated using the formula
A = 2·pi·r·h
A = 2·3.14·5·12
A = 2·60·3.14
A = 120·3.14
A = 376.8
You did ask for surface area, but your equation is wrong. The equation you gave,
2·Ï·r²·h
is the equation of the volume of the cylinder.
2007-08-26 20:39:15 · answer #2 · answered by ? 3 · 0⤊ 1⤋
Formula for surface area:-
A = 2(Ï r ²) + 2 Ï r h
A = ( 2 Ï r) (r + h)
A = (10 Ï) (17)
A = 170 Ï
A = 534.07 in ²
2007-08-26 21:15:47 · answer #3 · answered by Como 7 · 2⤊ 0⤋
600 * 3.1416 = 1884.96
2007-08-26 20:03:43 · answer #4 · answered by a r 3 · 0⤊ 1⤋
area = 2 Pi (5)^2 (12) = 1884.96 sq.in.
2007-08-26 20:06:37 · answer #5 · answered by CPUcate 6 · 0⤊ 3⤋