Mark as true any statement that is always true. Mark as false any statement that is never true or that is not necessarily true. Be able to justify your answers.

Question

1. If triangle ABC and triangle DEF are both 30–60 triangles, then AB must be congruent to
DE.
2. An angle of degree measure 180 is a reflex angle.
3. Postulates are statements we assume to be true without proof.
4. Any three points are contained in exactly one plane.
5. A right triangle has two acute angles.

Answer 1

1. F: The triangles may be different sizes and AB and DE may be different lengths.
2. F: An angle of degree measure 180 is a straight angle while a reflex angle has measure
180° 3. T
4. F—If the points are collinear they are contained in infinitely many planes.
5. T