SOLUTION: I have a pyramid with a square base on the bottom. Two of the sides are 20ft and L=18ft. I need to find the volume for this shape. Can you solve this for me please?

Algebra ->  Volume -> SOLUTION: I have a pyramid with a square base on the bottom. Two of the sides are 20ft and L=18ft. I need to find the volume for this shape. Can you solve this for me please?      Log On


   

Question 1181337: I have a pyramid with a square base on the bottom. Two of the sides are 20ft and L=18ft. I need to find the volume for this shape. Can you solve this for me please?
Found 2 solutions by MathLover1, ikleyn:
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

pyramid


if “Two of the sides” means side of the base a and L is slant height s
then we need height h
using Pythagoras theorem
h=sqrt%28L%5E2-%28a%2F2%29%5E2%29
h=sqrt%2820%5E2-%2818%2F2%29%5E2%29
h=sqrt%28400-81%29
h=sqrt%28319%29
h=17.86

then
V=%281%2F3%29a%5E2%2Ah
V=%281%2F3%2918%5E2%2A17.86
V=%281%2F3%29324%2A17.86
V=108%2A17.86057109949175
V=1928.94ft%5E3


Answer by ikleyn(52787) About Me  (Show Source):
You can put this solution on YOUR website!
.

For your info: 

(1)  Pyramids  do not have sides. 

     They have FACES, EDGES and VERTICES.



(2)  To solve the problem correctly, we need to know, which of the two given 

     edges is the side of the base square and which is the lateral edge.

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For what reason do you need the solution, when you do not know terminology ?

Learn terminology first.


On volume of pyramids,  see the lessons in this site

    - Volume of pyramids
    - Solved problems on volume of pyramids
    - Overview of lessons on volume of pyramids


If you will need more lessons on surface area or volume of solids,  let me know.

I will give you many other relevant links to my lessons.


Happy learning  (!)


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@MathLover1 starts her solution hypothesizing that

“Two of the sides” means side of the base a and L is slant height s.


This hypothesis  VERY  EASY  can be wrong / irrelevant,  and the slant height is  NEVER  considered as a  "side".
So be careful if her solution is applicable.

In Math,  serious teachers/tutors  DO  NOT  MAKE  such hypotheses,  when teach the student.

A serious tutor  REQUESTS  the student to provide a  RELIABLE  input.