Glencoe Math: Course 3, Volume 2
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Glencoe Math: Course 3, Volume 2 View details
5. Surface Area of Cones
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Exercise 23 Page 637

188.5 yd^2

Practice makes perfect

The given solid is a cone.

To calculate the surface area of a cone, we can use the known formula where r is the radius of the base and l is the slant height of the cone. S=Ï€ rl+Ï€ r^2 Looking at the diagram, we know that the radius of the cone's base is 3 yards and that the slant height of the cone equals 17 yards. By substituting r with 3 and l with 17 into the formula, we can calculate S.

S=Ï€ rl+Ï€ r^2
S=Ï€( 3)( 17)+Ï€( 3)^2
â–¼
Evaluate right-hand side
S=Ï€(3)( 17)+Ï€(9)
S=51Ï€+9Ï€
S=60Ï€
S=188.495559...
S≈ 188.5

The surface area of the cone is approximately 188.5 square yards.