Posted by sheila on Sunday, January 23, 2011 at 5:42am.
OPQRS is a regular squarepyramid whose base has sides of 7 cm. Given that the total surface area of the pyramid is 161 cm2, find its slant height.

pyramid  MathMate, Sunday, January 23, 2011 at 8:36am
It's similar to the previous question.
Start with drawing a diagram if the book did not supply one.
O is the vertex of the pyramid.
Let D be the centre of the rectangle PQRS, and A=centre of side PQ.
OAD is a right triangle where OD is the height=h, and OA is the height of the slant face OPQ.
By Pythagoras theorem, we find
OA²=sqrt(OD²+AD²)
=sqrt(h²+3.5²)
Area of one slant face
=AQ*OA
=3.5sqrt(h²+3.5²)
Area of 4 slant faces
=14sqrt(h²+3.5²)
Area of rectangular base
=7*7
=49
Equate the sum of areas to total surface area
14sqrt(h²+3.5²)+49=161
Solve for h. I get 7.2 approx. 
MATH! PLEASE REPLY ASAP!  no, Monday, April 6, 2015 at 10:50am
Se the methos
H^2= B^2+P^2 
MATH! PLEASE REPLY ASAP!  Abdullah, Monday, December 12, 2016 at 12:31am
answer will be 8

MATH! PLEASE REPLY ASAP!  Abdullah, Monday, December 12, 2016 at 12:33am
You people are just desyroying the math. be ashame ofvyourself you cannot give correct answer of even 1 question shame on yourself