Geometric Lines and Shapes Flashcards
Sector
The area of a proportion of a circle defined by the central angle
Straight angle
An angle measuring exactly 180°
Convex polygon
Polygon for which all interior angles are less than 180°; vertices seem to point outward; all diagonals will be contained within the polygon
Acute angle
And angle measuring between zero and 90°
Alternate interior angles
If a transversal intersects two parallel lines then the alternate interior angles are congruent
Acute triangle
Triangle with each angle being an acute angle; each angle measuring less than 90°
Right angle
And angle measuring exactly 90°. All right angles are congruent
Angle
The figure formed by the intersection of two rays, lines, or line segments, or else by two raise with a common endpoint
Vertical angles
The pair of opposite angles created when two lines intersect. the angles are congruent
Triangle similarity rule: angle-angle (AA)
If two angles of one triangles are congruent to angles of another triangle, The triangles are similar
Polygon
A multi sided, closed figure made up of vertices and edges
Irregular polygon
A polygon with sides and angle measures that are not all the same
Obtuse triangle
Triangle with one obtuse angle; one angle measuring more than 90°
Vertex
A point where to rays, lines, or line segments meet, such as the point where to rays, lines, or line segments intersect to form an angle
Diagonal
On a polygon, a line segment drawn from one vertices to another that is not a side
Triangle similarity rule: side-side-side (sss)
If the three sets of corresponding sides of two triangles are in proportion the triangles are similar
Inscribed angle
An angle made from points on a circle circumference
Incircle
A circle drawn on the inside of the polygon that touches the midpoint of each side
Total surface area
The sum of all of the areas of all faces of a solid object
Diameter of a circle
The length of a segment that goes from one point on a circle through its center, and continues on to the another point on the other side of the circle
Collinear
Lying on the same line
Quadrilateral
Polygon with four vertices and four sides (parallelogram)
Reflex angle
And angle measuring between 180° and 360°
Isosceles triangle
Triangle with at least two sides are congruent to each other and their two base angles congruent to each other
Chord
A line segment that connects two points on the circumference of a circle. The diameter is the longest cord in any give circle
Perimeter
The distance around the outside of a figure
Scalene triangle
Triangle with no sides or angles congruent to each other all three sides are of different lengths
Circumference
The perimeter of a circle. C=2(pi)r
Surface Area
The area of the outside surface of a three dimensional object
CPCTC: AAS
It’s two angles and the non-included side of one triangle are congruent to the corresponding parts of another triangle, the triangles are congruent
Complementary angles
The two angles that some to 90°
Rectangle
Parallelogram with for right 90° angles. both pairs of opposite sides are parallel. Sides do not need to be congruent but can be.
Plane
An infinite “surface” with no thickness that extends infinitely in all directions
Point
A location in space without any dimension
Similar Shapes
Shapes are similar when they have congruent angle measures and number of sides, but no different overall size
Supplementary angles
Two angles that sum to 180°
Congruent Shapes
Equal in measure, symbolized by ~=
Volume
The measure of the total three dimensional space contained inside an object
Equiangular Polygon
Polygon with all angles congruent (equal measure)
Radian
The unit of measure for angles. One Radian is the angle made at the center of a circle by an arc whose length is equal to the radius of the circle
Exterior angle of a polygon
The angle between a side and an adjacent side extended, on the exterior of a closed shape
Concave polygon
Polygon that has at least one interior angle that is more than 180°; at least one vertex seems to point inward; diagonals pass outside of the polygon
Alternate exterior angles
It’s a transversal intersex to parallel lines, then the alternate exterior angles are congruent
CPCTC: SSS
If three sides of one triangles are congruent to three sides of another triangle, then the triangles are congruent
Rhombus
Parallelogram with all sides of congruent length
CPCTC: SAS
If two sides and the included angle of one triangle are congruent to the corresponding parts of another triangle, the triangles are congruent
Equal lateral polygon
Polygon with all sides congruent
Vertices
The corners of the sheep
Line
An infinite set of points arranged straight in opposing directions, with infinite length and no thickness
Net
A two dimensional representation or pattern for a three dimensional object
Trapezoid
Quadrilateral with one pair of parallel sides and one pair of non-parallel sides
Lateral surface area
The sum of the areas of all faces including the bases of a solid object
Area
The amount of surface inside of a figure
Apothem
A line segment from the center of the polygon to the midpoint of a side
Right triangle
Triangle with one right angle measuring exactly 90°
Radius of a polygon
A line segment from the center of the polygon to a vertices
Square
Rectangle with four congruent sides four sides of the same measure
Corresponding angles
If a transversal intersects two parallel lines, the pairs of corresponding angles are congruent
Regular polygon
A polygon with all sides congruent to each other and all angle measures congruent to each other
CPCTC: RHS
In to right angled triangles, if the hypotenuse and one other pair of corresponding side lengths are equal the triangles are congruent 
Equilateral triangle/ equiangular triangle
A regular polygon of three sides; triangle with all sides congruent to each other and all angles are congruent to each other
Kite
Quadrilateral with two pairs of congruent sides that are adjacent to each other
Circle
The set of all points equidistant the same distance from a given point the center. Circles have no sides nor interior angles
Coplanar
Lying on the same plane
Radius of a circle
The distance from the center of a circle to a point on the circle
Interior angle
The angle formed on the interior of a closed shape
Face
The sides of the shape
Triangle
Polygon with three vertices and three sides
Secant
A line cutting through two points on a circle and extended chord
Triangle similarity rule: side-angle-side (SAS)
If an angle of one triangle is congruent to the corresponding angle of another triangle and the lengths of the sides including these angles are in proportion, the triangles are similar
Corresponding parts of congruent triangles congruency
When two triangles are congruent each part of the triangle is congruent to the corresponding part in the other triangle
Tangent
A line that touches the circle at one point only
Circumcircle
A circle drawn on the outside of a polygon that connects all the vertices
Obtuse angle
An angle measuring between 90° and 180°
Parallelogram
Quadrilateral with two pairs of opposite sides that are parallel to each other
Cyclic Quadrilateral
A quadrilateral inside a circle that has all four vertices as points on the circle circumference
Arc length
The measure of a section of the circumference of a circle
Edge
Where these faces meet
Central angle
Measurement in degrees or radians of an angle with its vertex on the center of the circle
