Copy of Exploring Angle Relationships with Triangles

Topic:
Triangles

Directions

For each of the following applets, explore the given angle relationships in order to make generalizations about the relationships between the angles.

Part I: Angle Sum in a Triangle

1. Add all 3 angles,what is the sum of the 3 angles?=_______________What do you notice about the measures of the angles in triangle ABC?_________________________ 2. Move points A, B, and C to create different triangles.  What do you notice about the angles in the new triangle?  __________________________Will this always be true?_________________ 3. Press the button that looks like a triangle and create a smaller triangle. Measure the three angles type the measurements here____________,_______________________,______________________. Add the 3 angles, what do they equal?__________________

8.G.A.5 Angle Sum

Part II: Exterior Angles 1

4. Angles BAD, CBE, and ACF are exterior angles of triangle ABC.  What do you notice about the exterior angles of this triangle? 5. Move points A, B, and C to create different triangles.  What do you notice about the exterior angles in the new triangles?  Will this always be true? 6. Add the two angles that are not near the third ________+____________=__________. What do they equal?__________________try it with one more set and see if it is the same.______________+____________=___________.

8.G.A.5 Exterior Angles 1

Part III: Exterior Angles 2

Angles CAH, ABI, and BCJ are also exterior angles of triangle ABC.  What do you notice about the angles of this triangle? Move points A, B, and C to create different triangles.  What do you notice about the exterior angles in the new triangles?  Will this always be true?

8.G.A.5 Exterior Angles 2