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A design for party favors are in the shape of a regular hexagonal pyramid. The hexagon has a side length of 6 inches. The lateral faces are isosceles triangles with equal sides of 9 inches.

The lateral area of the pyramid is:
A) 1082
B) 903
C) 965

And the base area is:
A) 362
B) 543
C) 245

1 Answer

5 votes

Answer:

Part 1)
LA=108√(2)\ in^2

Part 2)
B=54√(3)\ in^2

Explanation:

Part 1) Find the lateral area of the pyramid

we know that

The lateral area of the pyramid, is equal to the area of six congruent isosceles triangles

so


LA=6[(1)/(2)(b)(h)]

we have


b=6\ in

Applying Pythagorean Theorem calculate the height of triangle


9^2=(6/2)^2+h^2


h^2=81-9\\h^2=72\\h=√(72)\ in

simplify


h=6√(2)\ in

Find the lateral area


LA=6[(1)/(2)(6)(6√(2))]\\\\LA=108√(2)\ in^2

Part 2) Find the base area

we know that

The area of a regular hexagon is equal to the area of six equilateral triangles

so

Applying the law of sines to calculate the area of triangle


B=6[(1)/(2)b^2sin(60^o)]

we have


b=6\ in


sin(60^o)=(√(3))/(2)

substitute


B=6[(1)/(2)6^2((√(3))/(2))]


B=54√(3)\ in^2

User Kyle Challis
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