Question

Two angles of a triangle are in the ratio 4:5. If the sum of these angles is equal to the third angle find the angle?
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Answer 1

SoluTion

Let the Triangle be ABC

Given :-

∠A= 4x

∠B= 5x

∠C= ∠A+∠B

∠C= 4x+5x

∠C= 9x

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we use angle sum property

=> ∠A+∠B+ ∠C= 180°

=> 5x+ 4x+ 9x = 180°

=> 18x= 180

=> x= 180/18

=> x= 10°

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Let us verify that

to verify your answer we have to put 10° at the place of x

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=> ∠A+∠B+∠C= 180°

=> 4x+ 5x+ 9x= 180°

=> 4×10+5×10+9×10 =180°

=> 40+50+90 =180

=> 90+90+90=180

=> 180° = 180°

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∠A= 4x = 4×10 =40°

∠B= 5x= 5×10= 50°

∠C= 9x = 9×10 =90°

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Hence, angles of triangle are 40° , 50° , 90°