Download Acute Angle

Tangent
• Line that intersects the circle in
exactly one point.
Central angle
• For a given circle, an angle that
intersects the circle in two points and
has its vertex at the center of the
circle.
Chord
• For a given circle, a segment whose
endpoints are points on the circle.
Concentric circles
• Circles that lie in the same plane and
have the same center but have
different radii.
Diameter
• In a circle, a chord that contains the
center of the circle.
Inscribed angle
• An angle having its vertex lie on a
given circle and containing two
chords of the circle.
Major arc
• An arc on a circle greater than 180
degrees
Minor arc
• An arc on a circle less than 180
degrees
PI
• The ratio of the circumference of a
circle to its diameter.
Radius
A segment in a circle whose endpoints
are the center of the circle and a
point on the circle.
Secant
• For a circle, a line that intersects the
circle in exactly two points
Tangent of a circle
• A line in the plane of the circle that
intersects the circle in exactly one
point.
Circumference
• The distance around the circle.
• C = d∏ or C = 2∏r
Ratio
• The comparison of two numbers by
division.
Proportion
• An equation in the form a/c = b/d
that states that two ratios are
equivalent.
Acute Angle
• An angle whose
degree measure
is less than 90.
Coplanar
• Points that lie on the same plane
Vertical angles
• Two nonadjacent angles formed by
two intersecting lines.
Rectangle
• A quadrilateral with four right angles.
Altitude of a Triangle
• A segment from a vertex of the
triangle to the line containing the
opposite side and perpendicular to
the line containing that side
Rhombus
• A quadrilateral with four congruent
sides.
Square
• A quadrilateral with four right angles
and four congruent sides.
Trapezoid
• A quadrilateral that has exactly one
pair of parallel sides.
Parallelogram
• A quadrilateral with two sets of parallel sides.
Regular Polygon
• A convex polygon with all sides
congruent and all angles congruent.
Adjacent angles
• Two angles in the same plane that
have a common vertex and a
common side, but no common
interior points.
Straight angle
• A figure formed by two opposite
rays.
Obtuse angle
• An angle with degree measure
greater than 90 and less than 180.
Transversal
• A line that intersects two or more
lines in a plane at different points.
Skew lines
• Lines that do not intersect and are
not in the same plane.
Parallel lines
• Lines in the same plane that do not
intersect.
Complementary angles
• Two angles whose degree
measures have a sum of 90.
Acute Triangle
• A triangle all of whose angles are
acute
Equiangular Triangle
• A triangle with all angles congruent.
Isosceles Triangle
• A triangle with at least two sides
congruent.
Equilateral Triangle
• A triangle with all sides congruent.
Vertex angle
• In an isosceles triangle, the angle
formed by the congruent sides.
Obtuse triangle
• A triangle with an obtuse angle.
Scalene Triangle
• A triangle with no two sides
congruent.
Perpendicular lines
• Two lines that intersect to form a
right angle.
Right Triangle
• A triangle with one right angle.
Collinear points
• Points that lie on the same line.
Pythagorean Theorem
• In a right triangle, the sum of the
squares of the measures of the legs
equals the sum of the square of the
measure of the hypotenuse.
Supplementary angles
• Two angles whose degree measures
have a sum of 180.