SPINNING LESSON & Circles in the Third Dimension

Warm-up: Compare the following shapes Surface Area. Which is largest? Smallest?

A.) Right Triangular Prism with height = 3 &

side length of base = 2.

B.) Right Triangle Pyramid with height = 3 & side length of base=2.

C.) Right Triangle Pyramid with slant height = 3 & side length of base = 2.

Explain your answers!

2

3

2

3 3

2

QuadrilateralsTriangles Regular Polygons Circles

Pris

ms

Pyr

amid

s

Circle Cylinder Cone

5

60

30

Find the Lateral Area of the cylinder in the sphere as shown. The radius of the Sphere is 8”

7

= 2*

The sphere- NOT LIKE THE CONE OR THE CYLANDER, BUT AS IMPORTANT

We Can Approximate the surface area of a sphere using thin cylinders.

y

Since we only know so far how to find the

30

45

60

Each Cylinder is 1 inch thick and the radius of the Sphere is 8 inches. Each group is assigned to find one lateral area

Formula for Area of a sphere is 4*π* r^2. What is the area of the half-sphere? What is our error?

Outer radius is 6 and inner radius is 2 & the height is 5. Find the total Surface Area of the figure rotated around the axis

6

2

5

Outer radius is 6 and inner radius is 2. Find the total Surface Area

5

6

2

Your kid sister is making a mini model of the Earth for science class. The radius of her foam earth is 10in. She wants you to pick up blue paint (that she will use for the water). The earth is 87% water. Every oz of paint will cover 1in^3. How much blue paint do you need to buy?

11in.

Suppose your parents ask you to put a fresh coat of paint on your mailbox (see figure). If they give you enough paint to cover 4200 in2, will you have enough for 2 coats?

30in 14in