Proofs & Reasoning Flashcards
7 cards from real Geometry practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Proofs & Reasoning flashcards as text
What is the contrapositive of 'If a shape is a triangle, then it has three sides'?
Answer: If a shape does not have three sides, then it is not a triangle
The contrapositive negates and swaps both parts, and is logically equivalent to the original.
In a two-column proof, the left column contains statements and the right column contains:
Answer: Reasons or justifications
Each statement in a two-column proof must be justified by a reason on the right.
Which pairs of angles are always congruent when two lines intersect?
Answer: Vertical angles
Vertical angles formed by intersecting lines are always congruent.
The statement 'a = a' is an example of which property of equality?
Answer: Reflexive property
The reflexive property of equality states that any quantity equals itself.
If two angles form a linear pair, their measures add up to:
Answer: 180 degrees
Angles in a linear pair are supplementary, summing to 180 degrees.
Which statement is accepted as true without proof and used as a starting point?
Answer: Postulate
A postulate (or axiom) is a basic assumption accepted without proof.
The symmetric property of equality states that if a = b, then:
Answer: b = a
The symmetric property allows an equality to be reversed.