Polygons• Two-dimensional

shapes that have three or more sides made from straight lines.

• Examples:– triangles– squares– rectangles

Sides

• The lines you can trace and count on the outside of a 2D shape.

• Example: A triangle has 3 sides. A square has 4.

Parallelogram• A quadrilateral with

parallel opposite sides of equal length.

• Opposite angles are equal.

Quadrilaterals• Any two-dimensional

shapes (polygon) with 4 straight sides and 4 angles

• The interior angles of a Quadrilateral add up to 360 degrees.

• Ex. rhombus kite rectangle trapezoid

square

Rectangle• A 2D shape with 4

corners and 2 pairs of opposite, equal, parallel sides.

• The sides meet at right angles.

Rhombus

• A 2D, four-sided shape with opposite sides that are parallel.

• All the sides are the same length.

Rhombus• A 2D, four-sided

shape with opposite sides that are parallel.

• All the sides are the same length.

• Diagonals of a Rhombus bisect each other at right angles.

Trapezoid• A 2D shape (polygon)

with four sides. • One pair of sides is

parallel.

Trapezoid

• A 2D shape (polygon) with four sides.

• One pair of sides is parallel.

Square• 2D shape (polygon)

with 4 equal sides and 4 right (90°) angles.

• Opposite sides are parallel.

Triangle• Two-dimensional

shape (polygon) with three straight sides and three angles.

• The interior angles of a triangle add up to 180 degrees.

• There are – isosceles triangles,– right triangles– equilateral triangles– scalene triangles

Isosceles Triangle

• A triangle with 2 equal sides and 2 equal angles

Equilateral Triangle

• A triangle with 3 equal sides and 3 equal angles.

Right Triangle

• A triangle with one right angle (90 degrees).

Scalene Triangles• A triangle with 3

different side lengths and 3 different angle measures.

Congruent• Two figures are

congruent if they have the same shape and size.

• Two angles are congruent if they have the same measure.

Rectangular Prism• A 3D shape that has:

– 6 rectangular faces• 2 of those faces are

equal– 12 edges– 8 vertices

• Some faces are parallel• Some edges are parallel• Some faces are perpendicular• Some edges are perpendicular

Pyramid• A three-dimensional

shape which has a polygon for its base and triangular faces which meet at one point (vertex).

Cube• A three-dimensional

shape which has 6 square faces all the same size, 12 edges and 8 vertices.

• Some faces parallel• Some edges parallel• Some faces perpendicular• Some edges

perpendicular

Line• An infinitely

long, thin, two-dimensional mark

• It has no endpoints.

Line Segment• A section of line

bounded by two endpoints.

• A line segment is not continuous.

Intersecting• Crossing over one

another.

• These lines are intersecting.

Parallel• Lines that are the

same distance apart from each other.

• These type of lines stay the same distance apart for their whole length. They do not need to be straight or the same length.

• They never intersect.

Perpendicular• Lines that intersect at

a perfect right angle (90º) to one another.

• In solid shapes, edges could be at a right angle to one another.

• Faces could also be at right angles to one another.

Angles• A shape formed

by two lines or rays that extend from a common point (vertex).

• The amount of turning between two lines that meet at a common point (vertex).

Vertex (angles)• The common

point between two or more rays or line segments.

Right Angle

• An angle whose measure is exactly 90 degrees.

Symmetry• An object is

symmetrical when you can fold it in half and the two halves are congruent.

• One half is a mirror image of the other.

Symmetrical Not Symmetrical