2.2a Surface Area
Warm-up
a) 5.2 m2 = _______________ cm2
b) 78 cm2 = ______________ mm2
c) 3.4 yd2 = ______________ in2
d) 8145 ft2 = ____________ yd2
e) 0.37 km3 = ____________ m3
f) 5.4 ft3 = ______________yd3
g) A box in the shape of a rectangular prism measures 0.8 m by 0.6 m by 0.6 m. A
second box measures 2.5 ft by 2 ft by 2 ft. Determine, to the nearest cm3,
which box has the greater volume and by how much?
Surface Area of a Cone
Net:
SAcone = πr2 + πrs
Examples:
• Calculate the surface area of a right cone
that has radius 3.5 m and slant height 12 m.
• Calculate the unknown dimension:
a) A right cone has surface area 20 ft2
and radius 2 ft. Find the slant height.
Ch 2 SA and Volume Page 1
and radius 2 ft. Find the slant height.
Surface Area of a Sphere
SAsphere = 4πr2
or
SAsphere = πd2
Examples:
• Calculate the surface area of a sphere has diameter 8.5 in.
• Calculate the radius given a sphere with surface area 450 in2.
Surface Area of a Pyramid
SApyramid = sum areas of triangles + area of base
Square-based pyramid:
Remember area of triangle =
Examples:
• Calculate the surface area of a pyramid that has a
square base with sides 4 ft and slant height 5.5 ft.
Ch 2 SA and Volume Page 2
• Given the surface area, find the missing dimension.
7 cm
SA = 401.4 cm2
x
15 cm
Suface Area of a Cylinder
SAcylinder = 2πr2 + 2πrh
• If a cylinder has a surface area of 406.15 cm2
and a diameter of 6.4 cm. Find the height.
Assignment: p74 #1-5 (Do all letters)
Ch 2 SA and Volume Page 3