Asuna

1. Hamjamiyat
2. Study Group
3. hypotenuse of an oblique triangle

With a line perpendicular to the base of the triangle, the oblique triangle is divided into two right triangle and then we can "apply" the law of sines. 

1. Hamjamiyat
2. Study Group
3. hypotenuse of an oblique triangle

thanks! I understand it now.