Task:
Surface area of a regular square pyramid with the slant height of 7 and base perimeter of 10.
Solution:
Square Based Pyramid
Surface Area
A=2bs+b2
Perimeter of square whose four sides have length b is P=4b, hence we obtain b=4P.
b=410=2.5
Surface Area is determined by A=2bs+b2, where s is slant height.
A=2⋅2.5⋅7+2.52=35+6.25=41.25
Answer: 41.25 square units.