### Home > INT2 > Chapter 12 > Lesson 12.2.1 > Problem12-69

12-69.

Carefully examine each diagram below and explain why the geometric figure cannot exist. Support your statements with reasons. If a line looks straight, assume that it is.

Review the triangle congruence conjectures from the Math Notes box.

1. The triangles should be congruent by $SSS ≅$, but $80° ≠ 50°$ and in congruent triangles all angles are equal as well.

1. The triangles should be congruent by $SAS ≅$, but $80° ≠ 90°$ and $40° ≠ 50°$ and in congruent triangles all angles are equal as well.

1. The triangles should be congruent by $SAS ≅$, but $10 ≠ 12$ and in congruent triangles all sides are congruent as well.

1. What do you know about isosceles triangles?