Line and angle proofs

The  exercise appears under the Geometry Math Mission. This exercise uses lines and angles to establish facts via rigorous proof.

Types of Problems
There are two types of problems in this exercise:


 * 1) Fill in the spaces to complete the proof: This problem has a proof of a statement with missing spaces. The student is asked to use the included diagram to fill in the template with statements that will complete the proof correctly.Laap1.png
 * 2) Select the best reasoning: This problem makes a true claim. The student is asked to select which line of reasoning best establishes the fact that is being claimed from a multiple choice list.Laap2.png

Strategies
Knowledge of line and angle theorems being proved would assist with accuracy and efficiency, but generally only basic definitions are needed to ensure success on this exercise.
 * 1) Complementary angles add up to 90 and supplementary angles add up to 180.
 * 2) The last line of a proof is generally the statement that was supposed to be proved.
 * 3) A complement to an angle that measures x degrees is 90-x degrees, and a supplement is 180-x.
 * 4) Some of the proofs call upon the triangle congruence theorems (for example, SAS or SSS).

Real-life Applications

 * 1) Understanding the relationships between angles is important in drafting, mapping and architecture.