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6.1 POLYGONS
6.1 POLYGONS
VOCABULARYPolygon: plane figure formed by three or more segments (called sides).
Diagonal: segment that joins 2 non-consecutive vertices
CLASSIFYING POLYNOMIALSName # of Sides Sketch
Triangle
Quadrilateral
Pentagon
Hexagon
Heptagon
Octagon
Nonagon
Decagon
EXAMPLE 1Is the figure a polygon? Explain your reasoning.
QUADRILATERALS Quadrilateral Interior Angles Theorem
The sum of the measures of the interior angles of a quadrilateral is 360°
EXAMPLE 2Find the measure of the missing angle within each quadrilateral.
6.2 PROPERTIES OF PARALLELOGRAMS
Parallelogram: quadrilateral with BOTH pairs of opposite sides parallel
THEOREMS ABOUT PARALLELOGRAMS
1) If a quadrilateral is a parallelogram, then its opposite sides are congruent.
2) If a quadrilateral is a parallelogram, then its opposite angles are congruent.
3) If a quadrilateral is a parallelogram, then its consecutive angles are supplementary.
EXAMPLE 1FGHJ is a parallelogram. Find JH and FJ.
EXAMPLE 2PQRS is a parallelogram. Find the missing angle measures.
YOU TRY IT…Find the missing side lengths or angle measures as indicated.
ONE MORE THEOREM…If a quadrilateral is a parallelogram, then its diagonals bisect each other.
REMEMBER: to BISECT a segment means to divide the segment into two congruent segments.
EXAMPLE 3TUVW is a parallelogram. Find TX.
