surface area of cylinders and hw

Surface Area of Cylinders

Unroll a cylinder to see what shapes make up a cylinder.

You have to find the area of the rectangle and the two circles.

Given the radius of the circle and the height of the cylinder, how are you going to be able to do that?

Area of the circles (bases) = 2πr²

Area of the lateral rectangle = lw = (height of the cylinder)(circumference of the circle) or h(2πr).

So, the total surface area of the cylinder is

2πrh + 2πr²

You can use algebra to make the total surface area formula shorter:

2πrh + 2πr²

Find the total surface area of the cylinder.

3 cm

10 cmSA=_______________

SA=_______________

SA=_______________

8 cm

8 cm

SA=_______________

SA=_______________

SA=_______________

I want to wrap a gift that comes in a cylindrical canister that has a height of 18 in and a diameter of 3 in. Will 175 in2 of gift wrap be enough to cover the gift? SA=_______________

SA=_______________

SA=_______________

Homework:P. 554-555 #12-15, 17, 19, 20 all

Show 3 steps!

1. Formula

2. Substitution

3. Answer w/label