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19 votes
19 votes
I need help I never got taught how to do this

I need help I never got taught how to do this-example-1
User Mihai Neacsu
by
2.9k points

1 Answer

13 votes
13 votes

Answer:

736cm²

Explanation:

The surface area of a regular pyramid is equal to:

area of the square base + 1/2ps

where p is the perimeter of the base and

s is the height of the slant line of the pyramid.

In your drawing s = 15cm and the base has four equal lengths of 16cm

So first find the area of the base. Since this is a square, the area is just the

length x the width or 16cm x 16cm = 256cm²

(p) is the perimeter of the base. Find this by adding all four side of the bottom square together which is 16cm + 16cm + 16cm + 16cm or 4 x 16cm which is 64cm.

You already were given (s) which is the height of the slanted side from the base to the pointed top. The drawing gives you this as 15cm.

So plugging all this into the formula, you get:

Surface Area = Area of Base + 1/2 p s

= 256 cm² + [1/2 ( 64cm )(15cm)]

= 256 cm² + {1/2 ( 960 cm²)]

= 256 cm² + 480 cm²

= 736 cm²

User Septi
by
2.8k points
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