A tower $150$ meter high is situated at the top of a hill. At a point $650$ meter down the hill the angle between the surface of the hill and the line of sight to the top of the tower is $12^\circ$ $30$ minutes. Find the inclination of the hill to a horizontal plane.
How would I solve this problem?
I made a right triangle but so I know one of the angle is $90^\circ$ the other one must $77^\circ$ degrees $30$ minutes and faces $650$ meter and the other is $12^\circ$ $30$ minutes and faces $150$ meters.
But what would I do?