Question

two angles of a triangle are in ratio 4:5.If the sum of these angles is equal to the third angle. Find the third angles.

Answer 1

Answer:

Let the measure of two angles be 4x and 5x and the third one is ( 4x + 5x ).

We know that ;

Sum of angles of triangle = 180°

⇒ 4x + 5x + 4x + 5x = 180

⇒ 18x = 180

⇒ x = 180/18

⇒ x = 10

Therefore, the angles are ;

• 4x = 4 * 10 = 40°
• 5x = 5 * 10 = 50°
• 9x = 9 * 10 = 90°

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Answer 2

Answer:

The third angle is 90 ° .

Step-by-step explanation:

Given -

Two angles of a triangle are in ratio 4:5.

The sum of these angles is equal to the third angle.

To find -

The third angle

Solution -

Let, two angles are $4x$ and $5x$ .

As per the given information ,

The sum of these angles is equal to the third angle .

$4x+5x=9x$

So, The third angle is $9x$ .

As we know that,

The sum of all angles of triangle is 180° .

$4x+5x+9x =180$°

$18x=180$

$x=\frac{180}{18}$

Divide 180 by 18 we get

$x=10$

Angle becomes ,

$4x= 4 \times 10=40$ °

$5x= 5 \times 10 = 50$ °

$9x = 9 \times 10 =90$ °

∴ The third angle is 90 ° .