<p> 8.7 Surface Area – Day 2</p><p>Investigation 2: Surface Area of Pyramids</p><p>1.) If you wanted to find the surface area of the square pyramid below, what measurements would you need in order to find the surface area?</p><p>2.) Make up numbers for those measurements and find the surface area of the pyramid. Show all work.</p><p>3.) Suppose you had a pyramid whose base was a regular n-gon (making all of the lateral faces identical triangles.) See illustration below.</p><p> a.) Write a formula for each of the triangular lateral faces. (Use the variables from the picture above.)</p><p> b.) Write a formula for all of the triangular faces combined.</p><p> c.) Write a formula for the base (remember, it looks like an octagon, but we are going to use n for the number of sides.) Note: we wrote this formula when we did section 8.4, you just have to remember it.</p><p> d.) Using your answers from part b and c, write a formula for the surface area of any pyramid with a regular polygon base. 4.) The great pyramid in Egypt has a square base with side length of about 756 feet, a height of about 481 feet and a slant height of about 612 feet. Use your formula to calculate the surface area.</p><p>Investigation 2: Surface Area of a Cone</p><p>1.) Write an expression for the area of the base of the cone.</p><p>2.) Looking at the illustration, write an expression for the area of the lateral surface of the cone.</p><p>3.) Write a formula for the surface area of the cone.</p><p>4.) The ice cream cone below has a slant height of 3 inches and a diameter of 1 7/8 inches. Use your formula to find the amount of “cone” needed to make the cone.</p>