Question 1039574
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S=smallest angle;F=first angle=3S-20; T=third angle=4S
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S+F+T=180  , Sum of angles of a triangle is 180 degrees.
S+(3S-20)+4S=180 . Substitute for F and T
8S=200 . Add 20 to each side.
S=25 . Divide each side by 8
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F=3S-20=3(25)-20=75-20=55
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T=4S=4(25)=100
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The third angle is largest and measures 100 degrees.