Question

Solve for b

10, b, 150degrees, 12degrees

Answer 1

Hello!

We have all angles of the triangle:

We will use the law of cosines. This relation is valid for all sides of any t

We have:

angle A = 12°

côté a = 10

angle B = 150°

This is therefore the first case of application of the sine law.

So:

`\sf (b)/(sin~B) = (a)/(sin~A)`

`\sf b =(sin~B~*~a)/(sin~A) = (sin~150~*~10cm)/(sin~12) = (arcsin~0.5~*~10cm)/(arcsin~0.2079116908) = (30~*~10cm)/(12) = (300cm)/(12) = \boxed{\sf25cm}`

b = 25cm