Triangle Sum Theorem Exploration Tools needed: Straightedge, calculator, paper, pencil, and protractor z Step 1: Use a pencil and straightedge to draw 3 large triangles - an acute, an obtuse and a right triangle. Label the angles of the triangle as 1, , 2 2, and 3. See illustration to the right. Step 2: Measure the angles of each triangle and complete the table below. Type of Triangle m