# Geometry Chapter 7

## 30 terms

### Convex

A polygon that, for each pair of points inside the polygon, the line segment connecting them remains inside the polygon

### Concave

A polygon that, for each pair of points inside the polygon, the line segment connecting them lies outside the polygon

### Consecutive

Sides or angles of quadrilaterals that intersect

### Opposite

Sides or angles of quadrilaterals that don't intersect

### Diagonal

Of a polygon, a line segment that connects any two opposite vertices

Theorem: The ___ of the angles of a _________ is _____°

### Rectangle

A quadrilateral each of whose angles is a right angle

### Equiangular; rectangle

Corollary: A quadrilateral is ________ iff it is a _____

### Parallelogram

A quadrilateral whose opposite sides are parallel

### Symmetric with respect to a point

Two points iff the third point is the midpoint of the line segment joining them

### Opposite; angles; equal

Theorem: The _____ sides and _____ of a parallelogram are ____

### Diagonals; bisect

Theorem: The _____ of a parallelogram _____ each other

### Parallelogram; sides

Theorem: A quadrilateral is a ________ if its opposite ____ are equal

### Opposite angles

Theorem: A quadrilateral is a parallelogram if its ____ _____ are equal

### Sides; parallel

Theorem: A quadrilateral is a parallelogram if two of its opposite ____ are both ____ and equal

### Diagonals bisect

Theorem: A quadrilateral is a parallelogram if its ______ ______ each other

### Square

A quadrilateral with all equal sides and angles

### Rhombus

A quadrilateral all of whose sides are equal

### Rectangles

Theorem: All _____ are parallelograms

### Rhombuses

Theorem: All _____ are parallelograms

### Diagonals; rectangle

Theorem: The ______ of a ______ are equal

### Rhombus; perpendicular

Theorem: The diagonals of a ______ are _______

### Trapezoid

A quadrilateral that has exactly one pair of parallel sides

### Bases

The parallel sides of a trapezoid

### Legs

The sides of a trapezoid that include the bases

### Isosceles trapezoid

A trapezoid whose legs are equal

### Base; equal

Theorem: The ____ angles of an isosceles trapezoid are ____

### Diagonals; equal

Theorem: The ______ of an isosceles trapezoid are _____

### Midsegment

Of a triangle, a line segment that connects the midpoints of two of its sides

### The Midsegment Theorem

A midsegment of a triangle is parallel to the third side and half as long