2. Find lateral areas of cones. Find surface areas of cones.

3. Slant Height Right Cone The base is a circle and the vertex is point V The axis is the segment with endpoints that are the vertex and the center of the base. The segment that has the vertex as one endpoint and is ⊥ to the base is called the altitude of the cone. l V r Axis and Altitude

4. Axis Altitude Oblique Cone V l X

5. l V r r l

6. l V r r l Lateral Area= slant height x π x radius or L= πr l

7. 4cm4cm 12 c m Find the lateral area of the cone.

8. 4cm4cm 12 c m Find the lateral area of the cone. 1.L= πrl 2.L= π(4)(12) 3.L=150.8 Lateral area= 150.8cm 2

9. l V r

10. l V r T= πrl + πr 2

11. 6 m 8 m Find the surface area of the cone.

12. 6 m 8 m Find the surface area of the cone. 10 m 1.T= πrl + πr 2 2.Use Pythagorean theorem to find l. 3.T= π(6)(10) + π6 2 4.T= 301.6 Surface Area = 301.6 m 2

13. Johnny has an ice cream cone that has a lateral area of 28 in and a slant height of 6 In. Find the diameter of his ice cream cone.

14. 1.L= πrl 2.28= πr(6) 3.r ≈1.5 4.d ≈3 5.Diameter ≈ 3 inches