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### Course: Grade 7 (VA SOL)>Unit 7

Lesson 2: Surface area

# Surface area word problem example

Akira won a science fair and got a golden pyramid trophy. We want to find out how much gold foil was used. The trophy has a square base and four triangular faces. By calculating the area of these shapes, we can find the total surface area covered by the gold foil.

## Want to join the conversation?

• why do you have to multiply by 1/2?😕
• Since the triangle is half of a parallelogram, which is why you multiply it by 1/2.
• Any time you have a 3d surface area, do you have to unfold it all the time to find the area?
• No you can use formulas.
• It’s basically the surface area but without the base/s included
• Why do i have to do 5x3 if im finding the area of a box that has a height of 5 and a width of 3?
• b/c you find area by multiplying length and height
• Why do you have to combine the area of both figures?
• Because you are trying to find the total area.
• how do you find the height of a pyramid if you are given the slant height?
• The blue dotted line with the little square indicates it is the true height. You would not be able to have a slant with a 90 degree angle. The solid lines are the slants for the figure
• this is hard i had this for my homework and still i dont get it
• It's hard I agree. Try watching this and it might help you. https://youtu.be/7uzSWG6sRH0. Copy this and paste it to your search bar. It helped me better.
• Surface area is the area of the surface. In the video, Sal makes a net, basically making it flat, then calculating the area of each part and adding them up