Question

One of the angle of a triangle is equal to the sum of the other two angles. If the ratio of the other two angles is 4:5, then find the angle of the triangle.

Answer 1

Let the two angle be 4x and 5x, then third angle
=4x+5x=9x
So, 4x+5x+9x=180
18x=180
Therefore,. x=10
So, angle are 4x=4×10=40°
5x=5×10=50°
and 9x=9×10=90°

Answer 2

Step-by-step explanation:

Let the two angles of the triangle be 4x and 5x.

Then, as per the question, we know

third angle =4x+5x=9x

We know that sum of all the angles of a triangle is 180

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.

∴4x+5x+9x=180

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⇒18x=180

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⇒x=10

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....[On dividing both sides by 18]

So, first angle = 4x

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= 4×10

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=40

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,

second angle = 5x

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= 5×10

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=50

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and

and third angle = 9x

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= 9×10

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=90

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