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Geometry Chapter 3 Vocabulary Flashcards

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108760185alternate exterior anglesTwo nonadjacent exterior angles that lie on opposite sides of a transversal.108760185
108760186alternate interior anglesTwo nonadjacent interior angles that lie on opposite sides of a transversal.108760186
108760187axis of symmetryA line that divides a planar figureinto two congruent reflected halves.108760187
108760188center of a regular polygonThe point that is equidistant from all vertices of a polygon.108760188
108760189central angle of a regular polygonAn angle formed by two rays originating from the center of a circle.108760189
108760190concave polygonA polygon that is not convex.108760190
108760191convex polygonA polygon in which any line segment connecting two points of the polygon has no part outside the polygon.108760191
108760192corresponding anglesTwo nonadjacent angles, one interior and one exterior, that lie on the same side of a transversal.108760192
108760193equiangular polygonA polygon in which all angles are congruent.108760193
108760194equilateral polygonA polygon in which all sides are congruent.108760194
108760195midsegment of a trapezoidA line connecting the midpoints of the two nonparallel segments of a trapezoid.108760195
108760196midsegment of a triangleA segment whose endpoints are the midpoints of two sides.108760196
108760197polygonA closed plane figure formed from three or more segments such that each segment intersects exactly two other segments, one at each endpoint and no two segments with a common endpoint are collinear.108760197
108760198parallelogramA quadrilateral with two pairs of parallel sides.108760198
108760199quadrilateralA polygon with four sides108760199
108760200rectangleA quadrilateral with four right angles.108760200
108760201reflectional symmetryA plane figure has reflectional symmetry if its reflection image across a line coincides with the preimage, the original figure.108760201
108760202regular polygonA polygon that is both equilateral and equiangular.108760202
108760203remote interior angleAn interior angle of a triangle that is not adjacent to a given exterior angles.108760203
108760204rhombusA quadrilateral with four congruent sides.108760204
108760205rotational symmetryA figure has rotational symmetry if and only if it has at least one rotation image, not counting rotation images of 0˚ or multiples of 360˚, that coincides with the original figure.108760205
108760206same-side interior anglesInterior angles that lie on the same-side of a transversal.108760206
108760207slopeThe ratio of rise to run for a segment; the slope of a nonvertical line that contains the points (x1, y1) is the ratio (y2-y1/x2-x1)108760207
108760208squareA quadrilateral with four congruent sides and four right angles.108760208
108760209transversalA line, ray, or segment that intersects two or more coplanar lines, rays, or segments, each at a different point.108760209
108760210trapezoidA quadrilateral with one and only one pair of parallel sides.108760210
108767424Corresponding Angles PostulateIf two lines cut by a transversal are parallel, then corresponding angles are congruent.108767424
108767425Alternate Interior Angles TheoremIf two lines cut by a transversal are parallel, then alternate interior angles are congruent.108767425
108767426Alternate Exterior Angles TheoremIf two lines cut by a transversal are parallel, then same-side interior angles are supplementary.108767426
108767427Theorem:Converse of the Corresponding Angles PostulateIf two lines are cut by a transversal in such a way that corresponding angles are congruent, then the two lines are parallel.108767427
108767428Converse of the Same-Side Interior Angles TheoremIf two lines are cut by a transversal in such a way that same-side interior angles are supplementary, then two lines are parallel.108767428
108767429Converse of the Alternate Interior Angles TheoremIf two lines are cut by a transversal in such a way that alternate interior angles are congruent, then the two lines are parallel.108767429
108767430TheoremIf two coplanar lines are perpendicular to the same line, then two lines are parallel.108767430
108767431TheoremIf two lines are parallel to the same line, then the two lines are parallel.108767431
108767432The Parallel PostulateGiven a line and a point not on the line, there is one and only on line that contains the given point and is parallel to the given line.108767432
108767433Triangle Sum TheoremThe sum of the measures of the angles of a triangle is 180˚.108767433
108767434Exterior Angle TheoremThe measure of an exterior angle of a triangle is equal to the sum of the measures of the remote interior angles.108767434
108767435Sum of the Interior Angles of a PolygonThe sum,s, of the measures of the interior angles of a polygon with n sides is given by s = (n-2)180˚.108767435
108767436The Measure of an Interior Angle of a Regular PolygonThe measure, m, of an interior angle of a regular polygon with n sides is m=180˚-360/n.108767436
108767437Sum of the Exterior Angles of a PolygonThe sum of the measures of the exterior angles of a polygon is 360˚.108767437
108767438Parallel Lines TheoremIn a coordinate plane, two nonvertical lines are parllel if and only if they have the same slope.108767438
108767439Perpendicular Lines TheoremIn a coordinate plane, two nonvertical lines are perpendicular if and only if the product of their slopes is -1.108767439
109437795Converse of the Alternate Exterior Angles TheoremIf 2 lines are cut by a transversal in such a way that alternate exterior angles are congruent.109437795

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