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2. Find the surface area of the pyramid. Round to the nearest tenth.

9 in.
A. O 187.1 in²
B.O 233.8 in²
C.O 295.1 in²
D. 140.3 in²

2. Find the surface area of the pyramid. Round to the nearest tenth. 9 in. A. O 187.1 in-example-1
User Dapangmao
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1 Answer

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Answer:

To find the surface area of a pyramid, we need to use the formula:

Surface Area = Base Area + [ (Perimeter of Base) x (Slant Height) ] / 2

Assuming the base of the pyramid is a square with sides of length 9in, the Base Area = 9in x 9in = 81in²

To find the slant height, we need to use the Pythagorean theorem:

( Slant Height )² = ( Height )² + ( 1/2 Base )²

( Slant Height )² = ( 9/2 )² + ( 9/2 )²

( Slant Height )² = 81/4 + 81/4

( Slant Height )² = 162/4

( Slant Height )² = 40.5

Slant Height = sqrt( 40.5 ) = 6.36in (rounded to two decimal places)

Perimeter of Base = 4 x Base = 4 x 9in = 36in

Now we can plug these values into the formula:

Surface Area = 81in² + [ ( 36in ) x ( 6.36in ) ] / 2

Surface Area = 81in² + ( 228.96in² ) / 2

Surface Area = 81in² + 114.48in²

Surface Area = 195.48in²

Rounding to the nearest tenth gives us answer A. O 187.1 in²

User Mkedobbs
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