. Geometry A POINT A point is an exact location in space. A point has no length or width. To identify a point you use a dot and name it with a capital letter. For example: point A would look like this - A . You would say this is “Point A.”

Geometry Line: A line is a straight path of points that never ends. It goes on forever in two directions. When you draw a line you name it by using any two letters on the line. Another way to name a line is to use a single small letter. . A . B a

. . Geometry A B Show arrowheads at both ends to show that The symbol for the line has arrowheads, just like the drawing of the line. Show arrowheads at both ends to show that the line goes on forever in both directions. WRITE: AB or BA or la SAY: line AB or line BA or line a.

. . . Geometry D C E F Types of lines: A horizontal line goes straight across like the horizon. HORIZONTAL LINES . . C D VERTICAL LINES A vertical line goes straight down. . E F

. Geometry A D E B C More lines: Intersecting lines: Intersecting lines are lines that cross. They cross at a point. For example, think about streets that meet and cross at intersections. . A B E D C Line AB intersects line CD at point E.

. Geometry J K M N More lines: PERPENDICULAR LINES When two intersecting lines meet to form square corners, they are called perpendicular lines. . J K M N Line JK is perpendicular to line MN. A square corner is a right angle.

. Geometry E F H G More lines: PARALLEL LINES Parallel lines are always the same distance apart. They will never cross, or intersect, one another, like railroad tracks. Line EF is parallel to line GH. . E F G H

Geometry Think of a line as a rope that never ends. You can cut the rope into pieces. Each piece is a segment of a the rope. LINE SEGMENT A line segment is a part of a line. You name a line segment by using its two endpoints. A B . Line segment AB or line segment BA.

Geometry RAY A ray is a part of a line. It has one endpoint and goes on forever in one direction. . O B Use the endpoint as the first letter when writing the name of a ray. endpoint When you see a little One-headed arrow, say “ray.” Ray OB

Geometry ANGLE An angle is formed when two rays meet at an endpoint. The endpoint is called the vertex of the angle. . B A C Point B is the vertex of the angle.

Geometry You can name an angle by writing the point on one ray, the vertex, and the point on the other ray. When you see a sharp corner symbol say “angle.” . B A C Angle ABC or angle CBA The vertex is always written in the middle.

Geometry . ACUTE ANGLES M N O KINDS OF ANGLES You can name angles by how the measure compared to 90 degrees. ACUTE ANGLES Acute angles measure less than 90 degrees. . N M O Angle MNO is less than 90 degrees so it is an ACUTE angle!

Geometry . OBTUSE ANGLES M N O KINDS OF ANGLES You can name angles by how the measure compared to 90 degrees. OBTUSE ANGLES Obtuse angles measure greater than 90 degrees. . M N O Angle MNO is greater than 90 degrees so it is an OBTUSE angle!

Geometry . RIGHT ANGLES M N O KINDS OF ANGLES You can name angles by how the measure compared to 90 degrees. RIGHT ANGLES Right angles measure exactly 90 degrees. . M N O Angle MNO is 90 degrees so it is a right angle!

Geometry KINDS OF ANGLES A straight angle measures 180 degrees. It looks like a straight line. STRAIGHT ANGLES M N O .

Geometry Polygons A polygon is a closed figure whose sides are all line segments. Not Polygons Polygons

Geometry Polygons hexagon 6 sides The name of a polygon depends on the number of sides it has. triangle 3 sides quadrilateral 4 sides pentagon 5 sides hexagon 6 sides octagon 8 sides

Geometry Polygons The name of a polygon depends on the number of sides it has. A polygon that has all sides the same length and all angles the same measure is called a regular polygon.

Geometry Quadrilaterals A quadrilateral has 4 sides. Some quadrilaterals have more than one name. This quadrilateral is also called a trapezoid. A trapezoid has exactly one pair of parallel lines.

Geometry Quadrilaterals A quadrilateral has 4 sides. These quadrilaterals are also called parallelograms. A parallelogram has two pairs of sides that are the same length and are parallel. The sides marked in red are parallel to each other. They are the same length. The sides marked in green are parallel to each other. They are the same length.

Geometry Let’s look at just the parallelograms! Each of these two parallelograms is also called a rhombus. A rhombus has all sides the same length.

Geometry Let’s continue to just look at the parallelograms. Each of these two parallelograms is also called a rectangle. A rectangle has 4 right angles.

Geometry This figure is both a rhombus and a rectangle. It has all sides the same length and it has 4 right angles. It is called a square.

Geometry First: A triangle is a polygon with three sides. Triangles can be named two different ways. First: Named by its angles. All angles measure less than 90 degrees. One angle measures exactly 90 degrees. One angle measures more than 90 degrees. Acute triangle Right triangle Obtuse triangle

Geometry Second: Triangles can be named two different ways. Named by the length of its sides. All sides are the same length. Two sides are the same length. Each side is a different length. Equilateral triangle Isosceles triangle Scalene triangle

Geometry Solid Figures Solid figures have three dimensions: length, width, and height. Simple solid figure: CONES SPHERES PRISMS CYLINDERS PYRAMIDS

Geometry Names of Solid Figures prisms A 3-dimensional figure that has two congruent and parallel faces that are polygons. The rest of the faces are parallelograms.

Geometry Names of Solid Figures pyramids A 3-dimensional figure whose base is a polygon and whose other faces are triangles that share a common vertex.

Geometry Names of Solid Figures A 3-dimensional figure with two circular bases that are parallel and congruent.

Geometry Names of Solid Figures A 3-dimensional figure with one curved surface, one flat surface (usually circular), one curved edge, and one vertex.

Geometry Names of Solid Figures A solid figure made up of points that are all the same distance from a point called the center.

Geometry Parts of Solid Figures A face of a solid figure is a flat surface. An edge is a line segment where two faces meet. A vertex is a point where two edges meet, or the tip of a cone.

Geometry Parts of Solid Figures This figure has 6 faces, 12 edges, and 8 vertices. The plural of vertex is vertices.

Geometry Parts of Solid Figures Some faces are called bases. Prisms have two bases. A cylinder has 2 circular faces which are bases. A pyramid has 1 base and a face for each side of the base.

Geometry Solid Figures It unfolds to look like this! If you could cut a prism or pyramid along some edges, you could unfold the figure into a flat shape. This is a pattern for the figure and it is called a net. It unfolds to look like this! Triangular Pyramid

Geometry Solid Figures Here are some, but not all, nets for some prisms.

Geometry Solid Figures Here are some, but not all, nets for some pyramids.

Geometry Solid Figures Figures that have the same shape and size are congruent. When two figures are congruent, you can place one on top of the other and they will match exactly.

Geometry Solid Figures Congruent shapes can be turned and flipped.

Geometry Solid Figures In geometry, similar figures have the same shape. Sometimes they are the same size. Sometimes they are different sizes. Similar Not Similar

Geometry Symmetry Some figures can be folded in such a way that the parts of the figure match exactly. We say these figures have symmetry.

Geometry Symmetry The line where you fold the figure is called a line of symmetry.

Geometry Symmetry A figure may have more than one line of symmetry. A square has 4 lines of symmetry.

Geometry Symmetry NO NO YES YES NO YES Do the following figures have a line of symmetry? NO NO YES YES NO YES

Geometry Transformations When you slide a figure, it doesn’t change in any way except that it is now in a different place. Another name for a slide is a translation.

Geometry Transformations When you flip a figure across a line, the new figure looks like a reflection of the original figure. Another name for a flip is a reflection. The line is called a line of reflection. The two figures are mirror images of one another.

Geometry Transformations When you turn a figure, it spins around a point. It looks different, but it is still congruent to the original figure. Another name for a turn is a rotation.

Geometry Transformations What type of transformation is being shown?? turn or rotation slide or translation turn or rotation flip or reflection