SOLUTION: 1)The diagnosis of a square are 18 cm long. What is the area of the square?

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Question 973411: 1)The diagnosis of a square are 18 cm long. What is the area of the square?
Answer by macston(5194) About Me  (Show Source):
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.
Let D=diagonal=18cm; A=area of square
The diagonals of a square form 4 right triangles
with legs=1/2 the diagonal. Since the legs are also
base and height, the area of each triangle is Area of triangle=
1/2(b)(h)=(1/2)(1/2)(D)(1/2)(D)=(1/8)D^2. The total area is
4 of these triangles so A=(4)(1/8)(D^2)=D^2/2
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A=D%5E2%2F2 Put in value for D.
A=%2818cm%29%5E2%2F2
A=162cm%5E2
ANSWER: The area of the square is 162 square centimeters.