SOLUTION: One leg of an isosceles triangle has a length of (x2 + 9)cm. The base of the isosceles triangle has a length of (5x + 12)cm. The perimeter of the triangle is 42 cm. Find the val

Question 247459: One leg of an isosceles triangle has a length of (x2 + 9)cm. The base of the isosceles triangle has a length of (5x + 12)cm. The perimeter of the triangle is 42 cm. Find the value(s) for x and the lengths of the sides.
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
One leg of an isosceles triangle has a length of (x^2 + 9)cm.
The base of the isosceles triangle has a length of (5x + 12)cm.
The perimeter of the triangle is 42 cm.
Find the value(s) for x and the lengths of the sides.
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There are 2 equal legs and a base.
2(x^2+9) +5x+12 = 42
2x^2 + 5x + 18 - 42 = 0
2x^2 + 5x - 24 = 0
x = [-5 +- sqrt(25-4*2*-24)]/4
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x = [-5 +- sqrt(217)]/4
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Positive solution:
x = [-5+sqrt(217)]/4 = 2.4327..
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leg1 = leg2 = x^2+9 = (2.4327)^2+9 = 14.9182
base = 5x+12 = 24.1635
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Cheers,
Stan H.

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