Question

The surface area of this pyramid is one hundred eighty-nine square centimeters. The area of the square base is forty-nine square centimeters. What is the area of one triangular face of the lateral surface? Show the steps of your solution and explain your work.

a square pyramid

Answer 1

A square pyramid is formed by a square base and four triangular faces

surface area of pyramid = area of square + 4(area of triangle)
189 = 49 + 4(area of triangle)
area of triangle = (189 - 49) /4 = 140/4 = ???

Answer 2

Thank you! :)

Answer 3

No problem. :)

Answer 4

@LXelle where did you get 140
Can you explain the steps to me?

Answer 5

189-49 i got 140

Answer 6

Do you think you may have made some (TYPO's) in your work above? Because it is not making sense... @LXelle

Answer 7

surface area of pyramid = area of square + 4(area of triangle)
189 = 49 + 4(area of triangle)
area of triangle = (189 - 49) /4
= 140/4
= ???

makes more sense now?

Answer 8

Kind of...
Thanks, I will try to put the pieces together...

Answer 9

Which part you arent clear of?

Answer 10

Isnt 189-49/4 176

Answer 11

So where did you get 140 from?

Answer 12

Remember your BODMAS.

Answer 13

In this case i put bracket for (189-49) THERES A BRACKET. MEANS YOU GOTTA WORK OUT THE BRACKET FIRST.

Answer 14

Oh...

Answer 15

So now when you do the brackets first why do you have to divide by 4 isn't that gonna give you a different answer?

Answer 16

Noooo. I did the braacketed one first, I didnt divide the 4 to get 140. Only (189-49)= 140. Dont get confused.

Answer 17

thats why you see i did \[\frac{ (189-49) }{ 40 }\]

Answer 18

Oh...

Answer 19

So in the end the answer should be 35?

Answer 20

yes

Answer 21

My workings is just a guide for you. Try to work out your own workings. Youll understand better.

Answer 22

Okay thanks I got it now. :)

Answer 23

Okay. Glad that you got it! :)