SOLUTION: if triangle abc is isosceles, angle b is the vertex angle. ab=20x-2, bc=12x+30 and ac=25x, find perimeter of triangle abc

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Question 919813: if triangle abc is isosceles, angle b is the vertex angle. ab=20x-2, bc=12x+30 and ac=25x, find perimeter of triangle abc
Answer by MathLover1(20849) About Me  (Show Source):
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if triangle abc is isosceles, angle b is the vertex angle, ab=20x-2,+bc=12x%2B30 and ac=25x, find perimeter of triangle abc
Since the triangle is isosceles, ab=+bc}, so:
20x-2=12x%2B30 solve for x

20x-12x=2%2B3
8x=5
x=5%2F8
then
ab=20x-2
=>ab=20%285%2F8%29-2
=>ab=5%285%2F2%29-4%2F2
=>ab=25%2F2-4%2F2+
=>ab=21%2F2
=>ab=10.5
bc=12x%2B30
=>bc=12%285%2F8%29%2B30
=> bc=3%2A5%2F2%2B60%2F2
=> bc=75%2F2
=> bc=37.5
and
ac=25x
=> ac=25%285%2F8%29
=> ac=125%2F8
=> ac=+15.625
perimeter of triangle abc:
P=ab%2Bbc%2Bac
P=10.5%2B37.5%2B15.6
P=63.6