Card 1 of 20
EasyStudy card 1
Prompt
What defines a parallelogram?
Answer
A quadrilateral with two pairs of parallel opposite sides.
MathChapter 18: Polygons
Flashcards
Parallelograms Flashcards
Twenty cards on parallelogram and rhombus properties, diagonals, angles, heights, and areas.
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Card 1 of 20. Answer hidden.
Card 2 of 20
EasyStudy card 2
Prompt
What is true of opposite parallelogram sides?
Answer
They are parallel and congruent.
Card 3 of 20
EasyStudy card 3
Prompt
What is true of opposite parallelogram angles?
Answer
They are congruent.
Card 4 of 20
EasyStudy card 4
Prompt
What is true of consecutive parallelogram angles?
Answer
They are supplementary.
Card 5 of 20
EasyStudy card 5
Prompt
What do parallelogram diagonals do?
Answer
They bisect each other.
Card 6 of 20
EasyStudy card 6
Prompt
What defines a rhombus?
Answer
A parallelogram with four congruent sides.
Card 7 of 20
EasyStudy card 7
Prompt
What is the parallelogram area formula?
Answer
\(A=bh\), using perpendicular height.
Card 8 of 20
MediumStudy card 8
Prompt
If one parallelogram angle is 68°, what is an adjacent angle?
Answer
112°.
Card 9 of 20
MediumStudy card 9
Prompt
If diagonals meet at E, which parts of AC are equal?
Answer
\(AE=CE\).
Card 10 of 20
MediumStudy card 10
Prompt
What is special about rhombus diagonals?
Answer
They are perpendicular and bisect opposite angles.
Card 11 of 20
MediumStudy card 11
Prompt
What is the rhombus diagonal-area formula?
Answer
\(A=\tfrac12d_1d_2\).
Card 12 of 20
MediumStudy card 12
Prompt
A rhombus has diagonals 12 and 18. Find its area.
Answer
108 square units.
Card 13 of 20
MediumStudy card 13
Prompt
Why is a slanted side not automatically a height?
Answer
Height must be perpendicular to the chosen base.
Card 14 of 20
MediumStudy card 14
Prompt
Half-diagonals are 5 and 12. Find the rhombus side.
Answer
13, by the Pythagorean Theorem.
Card 15 of 20
MediumStudy card 15
Prompt
May general parallelogram diagonals be assumed congruent?
Answer
No; only bisection is guaranteed.
Card 16 of 20
MediumStudy card 16
Prompt
May general parallelogram diagonals be assumed perpendicular?
Answer
No; perpendicularity needs a rhombus or other evidence.
Card 17 of 20
HardStudy card 17
Prompt
Opposite sides are \(3x+4\) and \(5x-10\). Find x.
Answer
7.
Card 18 of 20
HardStudy card 18
Prompt
Why must half-diagonals be doubled before rhombus area?
Answer
The area formula uses full diagonal lengths.
Card 19 of 20
HardStudy card 19
Prompt
How do you validate algebraic parallelogram angles?
Answer
Opposites match, consecutive pairs total 180°, and every angle lies between 0° and 180°.
Card 20 of 20
HardStudy card 20
Prompt
Which markings prove more than appearance?
Answer
Parallel arrows, congruence ticks, right-angle squares, and matching angle arcs.
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