This
chart provides answers and hints. Try to reason about the properties on
your own and use hints only as the last resort. If the answer is YES or
NO, make sure to write down a complete proof - hints only provide general ideas that you need to supplement it with all necessary details.
If the answer is SOMETIMES, provide examples and
counterexamples.
For the area formulas, provide a clear justification.
Fill out each row from left to right (and top-down). Anything you prove can be used in the following boxes (to the right or above). This also means that to prove a property you can only assume things that are to the left of (or above) the box you are working on. You may also need to consult our minimal definitions of quadrilaterals and the guide for filling out this form.
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SIDES |
ANGLES |
DIAGONALS |
AREA |
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Parallel? |
Congruent? |
Congruent? |
Relationship? |
Congruent? |
Bisecting? |
Perpendicular? |
Triangle
Partition? |
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Kite |
Sometimes |
Yes – 2 pairs of adjacent
sides |
Yes – (at least) one pair of opposite
angles. Can you specify which pair of opposite angles is congruent? HINT |
Nothing remarkable |
Sometimes |
Yes – One diagonal always bisect the other HINT |
Yes HINT |
Two pairs of congruent
triangles. For concave kites, these triangles are fully or partially "outside "the kite. |
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Trapezoid |
Yes – (at least) one pair |
Sometimes |
Sometimes |
2 pairs of adjacent supplementary angles |
Sometimes |
Sometimes |
Sometimes |
One pair of triangles is similar. The other pair of triangles has the same area. |
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Isosceles
Trapezoid |
Yes – (at least) one pair |
Yes – one pair of opposite
sides. Can you specify which pair? HINT |
Yes – 2 pairs of angles adjacent to the bases. |
2 pairs of adjacent supplementary angles |
Yes |
Sometimes |
Sometimes |
One pair of triangles is similar. The other
pair of triangles is congruent. |
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Parallelogram |
Yes – two pairs |
Yes – 2 pairs of opposite sides HINT |
Yes – 2 pairs of opposite angles HINT |
Adjacent angles are supplementary (Hint - see the box above) |
Sometimes |
Yes |
Sometimes |
Two pairs of congruent triangles. |
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Rhombus |
Yes – two pairs |
Yes – all sides |
Yes – 2 pairs of opposite angles |
Adjacent angles are supplementary (Hint - see the boxes above) |
Sometimes |
Yes (Hint - Can you apply hint from parallelograms to rhombi?) |
Yes or Can you apply the hint from kites to rhombi? |
All triangles are congruent (Apply the previous hint (left box)) |
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Rectangle |
Yes – two pairs |
Yes – two pairs of sides HINT or try to apply the hint from Parallelograms |
Yes – all angles |
Any two angles are supplementary (Hint - see the previous box) |
Yes (Can you apply the hint from isosceles trapezoids?) |
Yes (Can you apply the hint from parallelograms?) |
Sometimes |
Two pairs of congruent triangles. (Can you apply the hint from parallelograms?) |
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Square |
Yes – two pairs (Hint - see Observation 1 in the hint for rhombi) |
Yes – all sides |
Yes – all angles |
Any two angles are supplementary |
Yes (Can you apply the hint from isoscleles trapezoids or rectangles?) |
Yes (Can you apply the hint from parallelograms?) |
Yes (Can you apply the hint from kites or rhombi?) |
All triangles are congruent (Can you apply the hint from rhombi?) |
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