Transcript 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?