Jewellery Stand

8th Grade Math Problems.?

1)Nancy made a cylindrical jewelry holder for her dresser. She covered one base and side with silver paper. If the holder was 12 centimeters tall and 14 centimeters wide, ABOUT how how much silver paper did Nancy use? (Use 3 for Pi) 2)The surface area of a cube is 192 cm squared. What is the area of each face? Answer and explain how you solved it thank you. ( These are surface area problems)

Public Comments

1. idk number 1. for number 2, i THINK it's 32 cm. there are 6 sides in a cube. 192/6=32 :D oh btw, im taking a guess. :O
2. if you draw the net unwrap the parts of a cylinder you get two circles ( base and top) and a rectangle the sides of the rectangle are pi*diameter or circumfernce of top/base times the height so 14*3(diameter * pi) * 12=504 area of face ( pi times radius squared) 7*7*3 = 147 147+504=651 6s^2=192 192/6=32 equals s(side) ^2 which is the area so 32
3. are you kidding me? il give you equations. plug and chug. number 1. wanted surface area=(height x width x pi) + (pi x 49) number 2. 196 divided by 6.
4. 1.Amt. of paper needed = Surface area to be covered = Area of the base + area of the sides = pi (rad)2 + 2. pi. (rad) height = 3 * 49 + 2 * 3 * 7 * 12 =651 sq.cm 2. 6 X a2 = 192 a2=32 a=5.66
5. for number 2, there are 6 faces. So the area of each face is 1/6 of the surface area. 192/6 = 32 square centimeters number 1, the surface area of a cylinder is 2*pi*r^2 + 2*pi*r*h for the entire thing since only one base is covered and one side then it must be half of the whole thing. or pi*r^2 + pi*r*h plugging numbers in to get: pi*7^2 + pi*7*14 = 49pi + 98 pi = 147pi 147*3 = 441 square centimeters