Geometry
Notes 11-6
Cones
Right Circular Conical surface:
Right Circular Cone: is the solid figure that is the union of a circular base
and the surface generated by line segments QP as P moves around the circle.
Lateral Surface Area of a Cone:
πrhs
Surface Area of a Cone:
2
πrhs + πr
hc hs
r
Volume of a Cone:
2
πr hc
Ex. 1: A right circular cone has a base with a radius of 10 inches, a height
of 24 inches and a slant height of 26 inches. Find the exact value of:
a. the lateral area
b. the area of the base
c. the total surface area of the cone
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Ex. 2: A cone and a cylinder have equal volumes and equal heights. If the radius
of the base of the cone is 3 centimeters, what is the radius of the base
of
the cylinder?
Ex. 3: The volume of a cone is 56 cubic centimeters and the area of the base
is 48 square centimeters. What is the height of the cone to the
nearest tenth?
Ex. 4: The highway department has a supply of road salt for use in the
coming winter. The salt forms a cone that has a height of 10 feet
and a circular base with a diameter of 12 feet. How many cubic ft
of salt does the department have stored? Round to the nearest
foot.
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