Verification of Exterior Angle Theorem
To verify the exterior angle theorem, which states that the exterior angle of a triangle is equal to the sum of two interior opposite angles, we will use a simple paper cutting and pasting method.

Materials Needed:
- A sheet of paper
- Scissors
- Glue

Procedure:
1. Start by drawing a triangle on the sheet of paper. Label the three vertices as A, B, and C.
2. Cut out the triangle carefully along its edges.
3. Extend one side of the triangle beyond the vertex to create the exterior angle.
4. Cut out the exterior angle portion.
5. Now, cut out the two opposite interior angles at the vertex where the exterior angle was created.
6. Paste the two interior angles together so that they form a straight line.
7. Now, paste the exterior angle next to the straight line formed by the interior angles.
8. You will notice that the exterior angle fits perfectly with the sum of the two interior opposite angles, proving the exterior angle theorem.

Conclusion:
By using the paper cutting and pasting method, we have visually verified that the exterior angle of a triangle is indeed equal to the sum of two interior opposite angles. This simple experiment helps to understand and remember this important theorem in geometry.