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Help me please with this

Help me please with this-example-1
User Kiding
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1 Answer

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Answer:

(b) 240

Explanation:

First, we use the Pythagorean formula using the given side lengths to find x. Then we use x to find the side lengths. Then we add the side lengths to find the perimeter.

Pythagorean theorem formula:

a^2 + b^2 = c^2

(x - 20)^2 + (x - 40)^2 = x^2

x^2 - 40x + 400 + x^2 - 80x + 1600 = x^2

x^2 -120x + 2000 = 0

(x - 100)(x - 20) = 0

x - 100 = 0 or x - 20 = 0

x = 100 or x = 20

We see that the solution x = 20 must be discarded because it will give a negative side length and a side length of 0. The only valid solution is x = 100.

perimeter = sum of the lengths of the sides

perimeter = x + x - 20 + x - 40

perimeter = 3x - 60

Replace x with 100.

perimeter = 3(100) - 60

perimeter = 300 - 60

perimeter = 240

User Phobos
by
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