# Math Help - SSA when the angle isn't between the sides - find the third side.

1. ## SSA when the angle isn't between the sides - find the third side.

Angle B is the obtuse angle in a triangle with the following measures. a=12, b=21, A=25 degrees. Find length c.

Not sure because have two sides, but not the angle between them.

GOT IT: Angle B comes out to 44.7, but since it's obtuse it's 180-44.7 = 132.3

2. ## Re: SSA when the angle isn't between the sides - find the third side.

Originally Posted by fcabanski
Angle B is the obtuse angle in a triangle with the following measures. a=12, b=21, A=25 degrees. Find length c.

Not sure because have two sides, but not the angle between them.

GOT IT: Angle B comes out to 44.7, but since it's obtuse it's 180-44.7 = 132.3
Use the sine rule to find angle B, then you will have two angles of the triangle, which is enough to find the third, then solve for side c using either the sine or cosine rules.