Fennels Flashcards
Parallelogram
A quadrilateral with two pairs of parallel sides
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If parallelogram, then…
- opposite side are congruent
- opposite angles congruent
- diagonals bisect each other
- consecutive angles are supplementary
If ____________, then parallelogram.
- one pair of opposite sides are parallel and congruent
- both pairs of opposite sides are congruent
- both pairs of opposite angles are congruent
- an angle is supplementary to both consecutive angles
- diagonals bisect each other
If rectangle, then…
- qualities of a parallelogram
- diagonals are congruent
- angles are right
If ____________, then rectangle.
- one angle is right
- diagonals are congruent and bisect each other
If rhombus, then…
- qualities of a parallelogram
- all sides are congruent
- diagonals are perpendicular
- diagonals bisect opposite angles
If ____________, then rhombus.
- one pair of consecutive sides is congruent
- diagonals are perpendicular
- one diagonal bisects opposite angles
Polygon Angle Sum Theorem
The sum of the interior angles of a convex polygon with (n) sides is 180(n-2) degrees.
Polygon Exterior Angle Sum Theorem
The sum of the exterior angle measures of a convex polygon is 360 degrees.
If square, then…
- qualities of a rhombus
- qualities of a rectangle
- diagonals create 4 congruent isosceles right triangles
If kite, then…
- diagonals are perpendicular
- exactly one pair of opposite angles is congruent
- two pairs of adjacent sides are congruent (all sides are NOT congruent)
If isosceles trapezoid, then…
- bases parallel
- legs congruent
- each pair of base angles is congruent
- diagonals are congruent
If trapezoid and ____________, then isosceles trapezoid.
- one pair of base angles is congruent
- diagonals are congruent
- legs congruent
Trapezoid Midsegment Theorem
The length of the midsegment of a trapezoid is half the sum of the base’s lengths.
Perimeters of Similar Polygons
If two polygons are similar, then their perimeters are proportional to the scale factor between them.
SSS Similarity
If the corresponding side lengths of two triangles are proportional, then the triangles are similar.
SAS Similarity
If the lengths of two sides of one triangle are proportional to the lengths of two corresponding sides of another triangle and the included angles are congruent, then the triangles are similar.
Triangle Proportionality Theorem
If a line is parallel to one side of a triangle and intersects the other two sides, then it divides the sides into segments of proportional lengths.
Converse of Triangle Proportionality Theorem
If a line intersects two sides of a triangle and separates the sides into proportional corresponding segments, then the line is parallel to the third side of the triangle.
Triangle Midsegment Theorem
A midsegment of a triangle is parallel to one side of the triangle, and its length is one half of the length of that side.
If similar triangles, then…
-lengths of corresponding altitudes, angle bisectors, and medians are proportional to lengths of corresponding sides
Triangle Angle Bisector
Separates the opposite side into two segments that are proportional to the lengths of the other two sides.
Congruent Arcs
In the same or congruent circles, two minor arcs are congruent if and only if their central angles/corresponding chords are congruent.
If the radius or diameter of a circle is perpendicular to a chord…
…then it bisects the chord and arc.