Polygon
Plane figure that is formed by three or more segments called sides. Each intersects exactly two other sides that at each of its midpoint.
Diagonal of a Polygon
Segment that joins two nonconsecutive vertices of a polygon
Parallelogram
quadrilateral with both pairs of opposite sides parallel
Rhombus
Parallelogram with four congruent sides
Rectangle
Parallelogram with four right angles
Square
parallelogram with four congruent sides and four right angles
Trapezoid
quadrilateral with exactly one pair of parallel sides
Isosceles Trapezoid
Trapezoid with congruent legs
Mid-Segment of a Trapezoid
Segment that connects the midpoints of the legs of a trapezoid
Perpendicular Bisector
line that is perpendicular to a segment at its midpoint
Reflection
Transformation that creates a mirror image
Line of Symmetry
Figure in the plane has a line of symmetry if the figure can be reflected onto itse;f by a reflection in the line
Congruent
Same side, arc, circle, figure, segment, angles
Vertical Angles
Two angles that are not adjacent and whose sides are formed by two intersecting lines
Proof
Convincing argument that shows why a statement is true
Vertex
Endpoint of a segment
Right Trianglee
Triangle with one right angle
Obtuse Triangle
Angle with measure between 90? and 180?
Hypontenuse
In a right triangle, the side opposite the right angle. Longest side of a right triangle
Equiangular Triangle
Triangle with three congruent angles
Isosceles Triangle
Triangle with a least two congruent sides
Equilateral Triangle
Triangle with three congruent sides
AAS
Two angles and a non-included side of one triangle are congruent to two angles
ASA
Two angles and the included side of one triangle are congruent to two angles
SAS
Two sides and the included angle of one triangle re congruent to two sides
SSS
Three sides of one triangle are congruent to three side of second triangle
HL
The Hypotenuse and a leg of a right triangle are congruent to the hypotenuse and a leg of a second right triangle