A sphere is a set of points in three dimensional space equidistant from a point called the center of the sphere. The distance from the center to the points on the sphere is called the radius of the sphere.

A quick review and missed information on a note card: How do you find the volume of a sphere? 4 π r ³ 3 r Add this formula to your volume note card!

How do you find the surface area of a polyhedron?

Find the surface area of this icosahedron. Hint: this is one of the Platonic solids! 10 cm What do you know about all of the faces? -regular triangles -congruent How do you find the area of a an equilateral triangle? A = ¼ √3 side ² 10 cm Area of 1 triangle = 25  3 How many faces are there? 500  3 cm²

Same idea - find the area of each face and add them all together What do the faces of a cylinder look like??? Joseph Campbell and Abraham Anderson formed a business that would one day become one of the most recognized in the world and serve as a symbol of Americana: Campbell Soup Company. This was in 1869, when Ulysses S. Grant was sworn into the Presidency. Take a closer look at some very famous cylinders to answer that question.

What about this? π r² height of can (h) goes around the circle circumference - 2 πr Area = 2 πr h

What about this? π r² Area = 2 πr h πr² ++ 2πr h 2πr² + 2πr h

6 ft 4 ft x2 r²r² h 2r2r 2  rh X 2 = SA = ft²

r²r² rlrl l l l = slant height  r l +  r² height l

3 cm 4 cm 5 cm  r l +  r²   3² cm²

r Surface area = 4  r² A sphere is basically made up of a bunch of layers of circles. What do you notice about the sizes of the circles? Where is the largest circle?

r Surface area = 4  r² Area of the largest circle or center of the sphere, called a great circle. It takes 4 great circles to cover the surface of the sphere.

18 m Surface area = 4  r² = 4  18² = m²

Try to find my surface area!! Kidding! There are other fun problems for you to do!