# MATH FINAL

## 85 terms · all of the vocab words for the final

### Acute Angle

An angle that has a measure that is less than 90 degrees°

### Acute Triangle

A triangle that has 3 acute angles.

### Adjacent Angles

Two angles that share a vertex, share one side, and whose interiors do not overlap.

### altitude

A segment in a triangle that is drawn from a vertex to the opposite side creating a right angle. The altitude is also known as the height of the triangle.

### Angle

Two rays that share an endpoint

### Angle Bisector

A ray that cuts an angle in half.

### Apothem

The distance from the center to the side of a regular polygon. The apothem always creates a right angle with the side of the polygon.

### Area

The number of square units that are contained within a 2 dimensional shape.

### Base

The two parallel sides in a trapezoid

### Bases

The non-congruent side in an isosceles triangle

### bisect

to cut an object in half

### central angle

An angle in a circle or a regular polygon that has the center as its vertex and each side of the angle is a radius

### chord

a segment in a circle whose endpoints are on the circle.

### centroid

The point in a triangle where all three medians of the triangle meet. The centroid is the balance point of any triangle.

### circle

a set of points that are equidistant from a center point

### circumference

distance around circle

### Common Vertex

The point where half of the edges in a pyramid meet.

### Complementary

Two angles whose measures add up to 90°.

### Concave Polygon

A polygon where at least one diagonal falls outside of the polygon. A polygon that has at least one interior angle that is larger than 180°.

### Congruent

Two objects that have the same size and same shape.

### Consecutive

Two angles that share a side but not a vertex and their interiors DO overlap.

### Convex Polygon

A polygon where all of the diagonals lie inside of the polygon. Every interior angle in a convex polygon will be less than 180°.

### Cosine

A trigonometric function that is a ratio of the adjacent side to the hypotenuse in a right triangle.

### Decagon

A polygon with 10 sides.

### Diameter

A chord that passes through the center of a circle.

### Dodecagon

A polygon with 12 sides.

### Equilangular

A polygon with all angles congruent.

### Equilateral

A polygon with all sides congruent.

### Heptagon

A polygon with 7 sides.

### Hexagon

A polygon with 6 sides.

### Hypotenuse

The longest side of a right triangle. It is always located across from the right angle.

### Inscribed angle

An angle in a circle whose vertex is on the circle and each side is a chord.

### Isosceles Triangle

A triangle that has two sides congruent.

### Kite

A quadrilateral that has two pairs of consecutive sides and one pair of opposite angles congruent.

### Legs:

1. The congruent sides of an isosceles triangle.
2. The two sides of a right triangle that are not the hypotenuse.
3. The non-parallel sides of a trapezoid. When the trapezoid is isosceles, the legs will be the ones congruent.

### Linear Pair

Two adjacent angles whose non-common sides form a line.

### Major Arc

A piece of a circle that measures between 180° and 360°.

### Mean

The average of a set of data.

### Median:

1. The middle value of a set of data.
2. A segment in a triangle that connects a vertex to the midpoint of the opposite side.

### Midpoint

A point that divides a segment in half. A segment bisector.

### Midsegment

1. In a triangle, it connects two midpoints of any two sides.
2. In a trapezoid, it connects the midpoints of the legs.

### Minor Arc

A piece of a circle that measures less than 180°.

### Mode

The element in a set of data that occurs the most often.

### Nonagon

A polygon with 9 sides.

### Obtuse Angle

An angle that has a measure between 90 and 180 degrees.

### Obtuse Triangle

A triangle that has one obtuse angle and two acute angles.

### Octagon

A polygon with 8 sides.

### Parallel

Two lines that never intersect and lie in the same plane. (same direction)

### Parallelogram

A quadrilateral whose opposite sides are parallel.

### Pentagon

A polygon with 5 sides.

### Perimeter

The distance around a polygon.

### Perpendicular

Two lines that create right angles when they intersect.

### Plane

A set of points that creates a flat surface.

### Point of Tangency

The point where a tangent intersects a circle.

### Polyhedron

A 3 dimensional figure that has polygons for faces. A polyhedron has no curves.

### Prism

A polyhedron that has two bases and rectangles as lateral faces.

### Protractor

A tool that is used to measure angles.

### Pyramid

A polyhedron that has one base and triangles for lateral faces.

### Quadrilateral

A polygon with 4 sides.

### Radius

A segment in a circle whose endpoints are the center and any point on the circle.

### Ray

Part of a line that has only one endpoint. It goes on forever in one direction.

### Reasons

The right side of a two - column proof. These are explanations for each step of the proof.

### Rectangle

An equiangular quadrilateral.

### Regular Polygon

A polygon that is equiangular and equilateral.

### Regular Polyhedron

A polyhedron that has congruent regular polygons as faces. There are only 5 regular polyhedrons that exist. These are also known as the Platonic Solids.

### Rhombus

An equilateral quadrilateral.

### Right Angle

An angle that measures exactly 90°.

### Right Triangle

A triangle that has one right angle and two acute angles.

### Scalene Triangle

A triangle that has 3 different side lengths.

### Secant Line

A line that intersects a circle in exactly two places.

### Segment

Part of a line that has two endpoints.

### Semicircle

A piece of a circle that measures exactly 180°.

### Similar

Two objects that have the same shape but different sizes.

### Sine

A trigonometric function that is a ratio of the opposite side to the hypotenuse in a right triangle.

### Skew

Two lines that will never intersect but are in different planes. (Different directions.)

### Slant Height

In a pyramid, the distance from the common vertex to the midpoint of an edge of the base.

### Square

A regular quadrilateral.

### Statements

The left side of a two - column proof. These are the steps to proof the given statement.

### Straight Angle

An angle that measures exactly 180°.

### Supplementary

Two angles whose measures add up to 180°.

### Surface Area

The total area of all the faces of a solid figure.

### Tangent:

1. A trigonometric function that is the ratio of the opposite side to the adjacent side in a right triangle.
2. A line that intersects a circle at exactly one point.

### Trapezoid

A quadrilateral that has exactly one pair of parallel sides.

### Vertex

The point where two sides of an angle meet.

### Volume

The amount of space inside a 3 dimensional object.