Download Surface Area of Pyramids

Surface Area of Pyramids
ADDITION TO DIAGRAM – NEW VOCAB
The slant height of a regular pyramid is
the distance from the vertex to the
midpoint of an edge of the base.
The lateral faces of a regular pyramid can
be arranged to cover half of a rectangle
with a height equal to the slant height of
the pyramid. The width of the rectangle is
equal to the base perimeter of the
pyramid.
Example 1
• Find the surface area of the regular
pyramid. n represents the number of
sides of the base, and s represents the
length of one side of the base, and l is
the slant height.
n = 3, s = 14, l = 14
Example 2
• Find the surface area of the regular
pyramid. n represents the number of
sides of the base, and s represents the
length of one side of the base, and l is
the slant height.
n = 6, s = 5.2, l = 13
Example 3
• Find the surface area of the regular
pyramid. n represents the number of
sides of the base, and s represents the
length of one side of the base, and l is
the slant height.
n = 4, s = 12, l = 13
Example 4
• Work backwards to solve for the
missing information.
In a rectangular pyramid, one side of the
base is 30 in. The slant height of the
pyramid is 29 in, and the SA = 4180
square inches. What is the length of
the other side of the rectangular base?
Example 5
• Work backwards to solve for the
missing information.
In a triangular pyramid, the base area is
50 square mm. The slant height of the
pyramid is 40 mm, and the SA = 250
square mm. What is the perimeter of
the triangular base?
Example 6
• Work backwards to solve for the
missing information.
In a square pyramid, the slant height is 5
cm, and the SA = 96 square cm. What is
the length of one side of the base?