In triangle ABC, angle C is 90 degrees, angle B is 60 degrees, find the sine of the outer angle BAD.

We know from the condition that the angle C = 90 ° in the triangle ABC, it is also known that the angle B = 60 °.

And we need to find the sin of the outer corner BAD.

We start by finding the degree measure of the angle of triangle A. To do this, we apply the theorem on the sum of the angles of a triangle. The angles of a triangle add up to 180 °.

Let’s calculate the angle A = 180 ° – (90 ° + 60 °) = 180 ° – 150 ° = 30 °.

The outer corner BAD is adjacent to corner A of the triangle. The sum of adjacent angles is 180 °:

180 ° – 30 ° = 150 °.

sin 150 ° = 1/2.

Answer: 1/2.