Question

In triangle ABC, find B, to the nearest degree, given a=7, b=10, and C is a right angle.

a. 35 degrees
b. 44 degrees
c. 46 degrees
d. 55 degrees

Answer 1

Option D is correct i.e angle B is 55°

Explanation:

Given In triangle ABC, a=7, b=10 and angle C is a right angle.

we have to find the angle B.

As given triangle is right angled triangle,

∴ we can apply the formula of trigonometric ratios to find the angle B

`tanB=(AC)/(CB)=(10)/(7)`

⇒
`B=tan^(-1)((10)/(7))=0.96 radian=55.0079^(\circ)\sim55^(\circ)`

Hence, angle B is 55°

Option D is correct.