How do u find the angles of a triangle whose sides are in the ratio 2:4:5?

Answer 1

one way is to use the law of cosines.

a^2 = b^2+c^2 - 2bc cosA

Without loss of generality, we may take a to be the smallest side, of length 2. Then,

2^2 = 4^2 + 5^2 - 2*4*5 cosA
A = 22.33
similarly,
B = 49.45
C = 108.22