Geometry Section - TEAS Review

Polygon

Is a closed, two-dimensional figure with 3 or more straight line segments called sides

By how many edges they have

How are polygons named?

Vertex

The point at which 2 sides of a polygon intersect

sides, equal, vertices

In a polygon, the number of ____ is always ____ to the number of ____

Edges

Sides of polygons

Vertices

Angles created where the edges intersect

Regular Polygon

Is a polygon with all sides congruent and all angles equal

Concave Polygons

Cannot be regular since all the vertices will never be the same measure

Triangle, quadrilateral, pentagon, hexagon, heptagon, octagon, nonagon, decagon, dodecagon

What are the common polgyons?

3

How many sides does a triangle have?

4

How many sides does a quadrilateral have?

5

How many sides does a pentagon have?

6

How many sides does a hexagon have?

7

How many sides does a heptagon have?

8

How many sides does a octagon have?

9

How many sides does a nonagon have?

10

How many sides does a decagon have?

12

How many sides does a dodecagon have?

n(n-3)

What is the formula for the total number of diagonal connections?

n(n-3)/2

What is the formula to figure out the number of unique diagonals?

Concave

Only polygons with 4 or more sides can be what?

Concave Polygons*

When one or more vertices of a polygon measures more than 180 degrees

Convex Polygon

All the vertices measure less than 180 degrees

Sum the 3 side lengths; a + b + c

How do you find the perimeter of a triangle?

Can be found by taking half the product of one side length; A = 1/2bh

How do you find the area of any triangle?

Quadrilaterals

Closed two-dimensional figure that has 4 straight lines

Kites

Is a quadrilateral with 2 pairs of adjacent sides that are congruent

They can be either

Can kites be concave or convex?

Yes, they have one line of symmetry

Do kites have a line of symmetry?

Perpendicular diagonals

What is the result from kites?

Trapezoid

Quadrilateral with at least one pair of parallel sides

Isosceles Trapezoid

Trapezoid with equal base angles

Makes the two nonparallel sides have the same length, the two non-base angles equal, and there’s one line of symmetry through the midpoints of the parallel sides

What components does the isosceles trapezoid make?

A = 1/2h(b1 + b2)

What is the formula for the area of a trapezoid?