Help please ! thank u

Question

asked Aug 23, 2022 25.7k views

1 Answer

Christopher Roscoe · Answer 1 · 2022-08-27T10:35:39+0000

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.