# How do you solve the triangle ABC given a=55, b=25, c=72?

##### 1 Answer

#### Explanation:

"Solve a triangle" means find all the missing information - in this case, the size of each angle.

The lengths of **3 sides** are given. We must use the **Cosine Rule.**

Find the biggest angle first - if it is an obtuse angle, the Cos rule will indicate this, but the Sin Rule will not,

Angle C is the biggest angle because it is opposite the longest side.

Now use the SIn Rule.

We have 2 angles, use the angle sum of a triangle to find