Mathematically, the obtuse angle is known, and the side length is also known as the calculated height. Sine and cosine theorems can be used to calculate the height.

Sine and cosine theorems are sine theorems and cosine theorems, which are important theorems to reveal the relationship between the angles of a triangle. Direct application can solve the problem of triangle. If the cosine theorem is transformed and properly transferred to other knowledge, it will be more convenient and flexible to use.