This applet is designed for students to investigate angle relationships of triangles. The students may know that the interior angles of a triangle sum to 180 degrees, but do they really understand why? Moreover, students are more likely to be unfamiliar with exterior angles of triangles, especially as compared to their remote interiors angles. This applet will help your students understand The Triangle Sum Theorem, The Exterior Angles Sum Theorem, and The Acute Angles Sum Corollary for Right Triangles. The hope is that the students can take their discovered ideas and develop a logical proof of each theorem and corollary described above.
