Here's a resource on finding the interior angles of a triangle using algebra. The triangle sum theorem states that the sum of the interior angles of a triangle equals 180 degrees. When expressed algebraically, the Triangle Sum Theorem transforms into an equation: ∠A+∠B+∠C=180∘.
 
There are ten (10) problems, and students will practice applying algebra to solve for unknown angles within triangles. The resource is available in digital and print formats. An answer key is included.