Question

Help please ! thank u

Answer 1

Given:

In triangle
`ABC,m\angle A=138^\circ,c=19,a=29`.

To find:

The
`m\angle C`.

Solution:

According to the law of sines:

`(\sin A)/(a)=(\sin B)/(b)=(\sin C)/(c)`

Taking
`(\sin A)/(a)=(\sin C)/(c)`, we get

`(\sin 138^\circ)/(29)=(\sin C)/(19)`

`(0.66913)/(29)* 19=\sin C`

`0.4383959=\sin C`

Taking sin inverse on both sides, we get

`sin(-1)0.4383959=C`

`26.001577^\circ=C`

`C\approx 26^\circ`

Therefore, the correct option is b.