Question

One of the angles of a triangle is equal to the sum of
the other two angles. If the ratio of other two angles
is 4:5, the greatest angle of the triangle is -
(A) 100°
(C) 70°
(B) 90°
(D) 85°​

Answer 1

Answer:

90

Step-by-step explanation:

it is right...............

Answer 2

Ratio of the 2 angles = 4:5

Let common ratio = x

Then, angles = 4x, 5x

Third angle = 4x+5x

= 9x

4x+5x+9x = 180°

18x = 180°

x = 180/18

x = 10°

Greatest angle = 9x

= 9×10

Greatest angle = 90°

Answer = (B) 90°