Unit 3 Words
Transversal
A line that intersects two coplanar lines at two distinct points.
Corresponding Angles
Angles that lie on the same side of the transversal and in corresponding positions relative to their coplanar lines.
Same-Side Interior Angles
Interior angles that lie on the same-side of the transversal.
Alternate Interior Angles
Nonadjacent interior angles that lie on opposite sides of the transversal.
Corresponding Angles Postulate
If a transversal intersects
two parallel lines, then
corresponding angles are
congruent.
Same-Side Interior Angles Theorem
If a transversal intersects two parallel lines, then alternate interior angles are congruent.
Alternate Interior Angles Theorem
If a transversal intersects two parallel lines, then same-side interior angles are supplementary.
Converse of Corresponding Angles Postulate
If corresponding angles are congruent, then a transversal intersects two parallel lines.
Converse of Same-Side Interior Angles Theorem
If same-side interior angles are supplementary, then a transversal intersects two parallel lines.
Converse of Alternate Interior Angles Theorem
If alternate interior angles are congruent, then a transversal intersects two parallel lines.
Equiangular Triangle
A triangle with all angles congruent.
Acute Triangle
A triangle with all acute angles.
Right Triangle
A triangle with one right angle.
Obtuse Triangle
A triangle with one obtuse angle.
Equilateral Triangle
A triangle with all sides congruent.
Scalene Triangle
A triangle with no congruent sides.
Isosceles Triangle
A triangle with at least 2 congruent sides.
Triangle Angle Sum Theorem
The sum of the measures of the angles of a triangle is 180.
Triangle Exterior Angle Theorem
The measure of each exterior
angle of a triangle
equals the sum of the measures of its two remote interior angles.
Polygon
A closed plane figure with at least three sides. The sides intersect only at their endpoints, and no adjacent sides are collinear.
Convex Polygon
A polygon with no diagonal outside the polygon.
Concave Polygon
A polygon with at least one diagonal outside the polygon.
Polygon Angle Sum Theorem
The sum of the measures of the angles of an n-gon is (n − 2)180.
Polygon Exterior Angle-Sum Theorem
The sum of the measures of the exterior angles of a polygon, one at each vertex, is 360.
Equilateral Polygon
A polygon with all sides congruent.
Equiangular Polygon
A polygon with all angles congruent.
Regular Polygon
A polygon that is both equilateral and equiangular.