In triangle ABC, angle C is 90 and angle B is 60. Find the sine of the angle BAD.

In triangle ABC we find sin BAD if the values are known:

Angle C is 90 °;
Angle B is 60 °.

Decision

Consider a triangle ABC. The sum of all the angles of a triangle is 180 °. Since we already know 2 angles, we can easily find the third angle, that is, angle A.

Angle A = 180 ° – 90 ° – 60 ° = 30 °;

Angle BAD is the outer angle from angle A.

Then:

Angle BAD = 180 ° – angle A = 180 ° – 30 ° = 150 °;

Hence, the Angle BAD = 150 °.