Solving Triangles
Exterior Angles Theorem - Solve for X, Geometry
Heron's formula - Wikipedia
How to Find the Measure of an Angle of a Triangle Given Angles with Variables, Geometry
How to Solve a Triangle When You Know Two Angle Measures - dummies
3 Ways to Find the Third Angle of a Triangle - wikiHow
Solving Equations Using Angle Relationships
How to find Angle Measures of an Isosceles Triangle Given Angles with Variables, Geometry
How Do You Find Missing Angles in a Triangle With Variables?