Terms in this set (61)
A line segment is part of a line lying between two points.
A ray is the part of a line lying on one side of a point on the line.
An angle is formed by two rays that share a common endpoint. The rays are called the sides of the angle and the common point is called the vertex.
An acute angle measures less than 90*
A right angle measures exactly 90*
An obtuse angle measures more than 90
but less than 180
A straight angle measures exactly 180* and forms a line.
A reflex angle measures more than 180
but less than 360
Complementary angles are two angles whose measures have a sum of 90*.
Supplementary angles are two angles whose measures have a sum of 180*.
Measure of an angle
The measure of an angle is the amount of rotation from one ray (the initial ray) to the second ray (the terminal ray).
Parallel lines are lines that lie in the same plane and do not intersect.
Perpendicular lines are two lines that intersect to form congruent adjacent angles; equivalently, they are two lines that intersect to form right angles.
Two or more figures are said to be congruent if they are the same size and have the same shape or component shape.
A polygon is a simple closed curve formed by a finite number of line segments.
A triangle is a polygon with three sides.
A quadrilateral is a polygon with four sides.
A pentagon is a polygon with five sides.
A hexagon is a polygon with six sides.
A heptagon is a polygon with seven sides.
An octagon is a polygon with eight sides.
A nonagon is a polygon with nine sides.
A decagon is a polygon with ten sides.
A diagonal of a polygon is a line segment that joins any two non-adjacent vertices.
A polygon is said to be convex if all it's diagonals lie completely in the interior of the polygon; otherwise, the polygon is concave.
A polygon is called regular if all it's interior angles have the same measure and all it's sides have the same length, a polygon is regular if all it's interior angles are congruent and all of its sides are congruent.
A scalene triangle is a triangle that has no congruent sides.
An isosceles triangle is a triangle that has at least two congruent sides.
An equilateral triangle is a triangle that has three congruent sides.
An equiangular triangle is a triangle that has three congruent angles.
A right triangle is a triangle that has a right angle.
An acute triangle is a triangle that has three acute angles.
An obtuse triangle is a triangle that has an obtuse angle.
A (proper) trapezoid is a quadrilateral that has exactly one pair of parallel sides.
A parallelogram is a quadrilateral in which both pairs of opposite sides are parallel.
A rectangle is a parallelogram with one right angle; equivalently, it is a quadrilateral that has four congruent angles.
A rhombus is a quadrilateral that has four congruent sides.
A square is a quadrilateral that has four congruent angles and four congruent sides. It is a rhombus that has one right angle. It is a rectangle that has four congruent sides. It is a regular quadrilateral.
A circle is the set of all the points in a plane that are a fixed distance from a fixed point in the plane. The fixed point is called the center of the circle.
A radius is a line segment with one endpoint at the center of a circle and the other endpoint on the circle. For a given circle, the length of a radius is the "fixed distance" in the definition of a circle.
A diameter is a line segment having endpoints on a circle and passing through the center of the circle. For a given circle, the length of diameter is twice the length of a radius.
A sphere is the set of all points in space that are a fixed distance from a fixed point.
A polyhedron is a simply closed surface composed of polygonal regions. The polygonal regions that make up the polyhedron are called faces. The sides of each polygonal region are called the edges of the polyhedron. The point where two edges meet is called a vertex.
A prism is a polyhedron with two congruent polygonal regions that are opposite faces. Corresponding vertices on each face are connected by parallel line segments. The opposite faces are called the bases of the prism. The faces that are not the bases are called lateral faces.
A pyramid is a polyhedron that has a polygonal base and triangular faces with a common vertex called the apex.
A cylinder is formed by two congruent parallel curved regions (not polygonal) connected along their boundaries by a surface.
A cone is formed by joining a curved region (not polygonal) and a point (called the apex) not in the region with a surface.
A rigid transformation of an object results in a change of location of the object, but not the size or shape of the object.
A translation of an object by a given distance in a given direction is the end result of moving each point in the object the given distance in the given direction.
A reflection of an object across a line L results in the same object where the line segments joining corresponding components in the object are perpendicular to L, and with distances to L preserved. L is called the line of rotation.
A rotation of an object about a point through a given angle is the end result of rotating all points in the object about the fixed point through the fixed angle. The fixed point is called the center of rotation. The fixed angle is called the angle of rotation.
A glide-reflection is the end result of combining a reflection and the a translation in the direction of the line of reflection.
Opposite angles formed by lines that intersect at one point are called vertical angles; sometimes, they are just called opposite angles.
Alternate interior angles
Alternate interior angles lie between the parallel lines and on opposite sides of the transversal.
Alternate exterior angles
Alternate exterior angles lie outside the parallel lines and on opposite sides of the transversal.
Corresponding angles lie on the same side of the transversal and in the same relative position with respect to their corresponding lines.
Two objects are similar if: corresponding angles are congruent, every point on one object corresponds to a point on the other object, and there is a positive number (k) such that the distance between two points on the second object is k times as long as the distance between the corresponding points on the first object for any pair of points. (The number k is called the scale factor)
The perimeter of an object is the total length of the outer edge of the object.
The circumference of a circle is the distance around the circle.
Area describes the size of something that is 2-dimensional. It is the number of square units
Required to cover a planar region without gaps or overlaps.
Volume describes the size of something that is 3-dimensional. It is the number of cubic units required to fill a space figure without gaps or overlaps.