133k views
3 votes
write and simplify an expression for the surface area of a square pyramid with a base edge length of s in. & triangular faces with a height of 7 in. What is the surface area if the base edge length is 2.5 in.?

User Katrasnikj
by
7.6k points

2 Answers

2 votes

Answer:

41.25

Explanation:

User EvgeniySharapov
by
7.8k points
4 votes

Answer:


A=14s+s^2


A=41.25\ in^2

Explanation:

-Let s be the base lengths and h be the slant heights of the trinagles.

-Surface area of the pyramid is the sum of the areas of all of it's face and can be given as:


Area=Area \ of \ Triangles +Base \ Area\\\\=4((1)/(2)sh)+s^2\\\\=2sh+s^2\\\\=s(2h+s)


h=7\\\\\therefore A=s(2h+s)\\\\=s(2* 7+s)\\\\=s(14+s)\\\\=14s+s^2

#We substitute the length and height dimensions in our simplified formula to calculate the Surface area as:


A=s(2h+s)\\\\=2.5(2* 7+2.5)\\\\=41.25\ in^2

Hence, the pyramid's surface area is
41.25\ in^2

User Krrishna
by
7.4k points