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Math III Unit IV Vocab
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Gravity
Terms in this set (61)
Acute angle
an angle whose measure is between 0° and 90°
Acute triangle
a triangle with three acute angles
Adjacent angles
two angles with the same vertex and a common side between them
Alternate exterior angles
when a line intersects two parallel lines, eight angles are formed; two angles that are outside (exterior) the parallel lines and on opposite sides (alternate) of the intersecting line are called alternate exterior angles
Alternate interior angles
when a line intersects two parallel lines, eight angles are formed; two angles that are between (interior) the parallel lines and on opposite sides (alternate) of the intersecting line are called alternate interior angles
Angle
the union of two rays with a common endpoint; angles are measured in a counterclockwise direction; the angle rays are labeled as initial and terminal sides with the terminal side counterclockwise from the initial side
Base angles of an isosceles triangle
the angles opposite the equal sides of an isosceles triangle are the base angles, which are also equal
Base of an isosceles triangle
the congruent sides of an isosceles triangle are called the legs, while the third side of the isosceles triangle is called the base
Complementary angles
two angles whose sum is 90°
Corresponding angles
if a line intersects two parallel lines, eight angles are formed; two non-adjacent angles that are on the same side of the intersecting line but one between the parallel lines and one outside the parallel lines are called corresponding angles
Diagonal
a line segment with endpoints on two nonconsecutive vertices of a polygon
Equiangular polygon
a polygon with all angles equal
Equiangular triangle
a triangle with all angles equal
Equilateral polygon
a polygon with all sides equal
Equilateral triangle
a triangle with all sides equal
Exterior angle
is an angle formed by one side of a polygon and an adjacent side extended
Geometry
the branch of mathematics that investigates relations, properties, and measurements of solids, surfaces, lines, and angles
Heptagon
a seven-sided polygon
Hexagon
a six-sided polygon
Hypotenuse
the side opposite the right angle in a right triangle
Interior angle
an angle that lies inside a polygon and is formed by two adjacent sides of the polygon
Intersect
to cross; two lines in the same plane intersect if and only if they have exactly one point in common
Isosceles trapezoid
a trapezoid whose non-parallel sides (or legs) are congruent
Isosceles triangle
a triangle with two sides equal
Kite
a quadrilateral with two pairs of adjacent sides congruent and no opposite sides congruent
Line
one of the undefined terms; consists of a set of points extending without end in opposite directions
Line segment
a subset of a line that contains two points of the line and all points between those two points
Nonagon
a nine-sided polygon
Obtuse angle
an angle that measures between 90° and 180°
Obtuse triangle
a triangle with one obtuse angle
Octagon
an eight-sided polygon
Parallel lines
lines in the same plane that do not intersect; the two lines are everywhere equidistant
Parallelogram
a quadrilateral whose opposite sides are parallel
Pentagon
a five-sided polygon
Perpendicular lines
two lines that form a right angle
Plane
a set of points that form a flat surface extending without end in all directions
Plane geometry
the branch of mathematics that deals with figures that lie in a plane or flat surface
Point
a location with no width, length, or depth
Polygon
a closed figure bounded by line segments
Quadrilateral
a polygon with four sides
Ray
a subset of a line that consists of a point and all points on the line to one side of the point
Rectangle
a parallelogram with four right angles and opposite sides are parallel and congruent
Reflex angle
an angle greater than a straight angle and less than two straight angles
Regular polygon
a polygon whose sides and angles are all equal
Rhombus (rhombi)
a parallelogram having two adjacent sides equal
Right angle
an angle whose sides are perpendicular; having a measure of 90 degrees
Right triangle
a triangle with one right angle
Scalene triangle
a triangle with no two sides of equal measure
Sides of a polygon
the line segments forming a polygon are called the sides of the polygon
Similar figures
figures with the same shape but not necessarily the same size
Similar polygons
polygons whose corresponding angles are congruent and whose corresponding sides are proportional; the symbol ~ is used to indicate that figures are similar
Square
a rectangle having two adjacent sides equal
Straight angle
an angle measuring 180°
Supplementary angles
two angles whose sum is 180°
Transversal
a straight line that intersects two or more straight lines
Trapezoid
a quadrilateral with exactly one pair of parallel sides
Triangle
a polygon with three sides
Vertex
the turning point of a parabola; the common endpoint of the two intersecting rays of an angle
Vertex angle of an isosceles triangle
the angle formed by the equal sides of the triangle
Vertex of a polygon
a point where two sides of a polygon meet
Vertical angles
two nonadjacent angles formed by two straight intersecting lines
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