Math Reference For Parents

Math Vocabulary and Notes: Unit 6

Congruent: Figures that have identical shapes but may face different directions, or orientations. (Same Shape Same Size)

Symmetry: Figures that can be divided equally into two identical parts.

“Symmetry Check; Near, Near, Middle, Middle, Far, Far, CHECK”

Axial Symmetry: If you can fold a shape in half so that both halves overlap perfectly, that shape has axial symmetry. That means that the form of the shape is the same on both sides of the axis.

Rotation Symmetry: When you trace an image and them place that rotate the image 180 ̊and if the traced image matched exactly, then you have rotational symmetry.

Measuring angles: Angle sign:     so    S means angle S You can write       SBC or      AC

·         Protractor: Used to measure an angle, measured in degrees.

·         Right: Measures exactly 90® degrees. (“Right angels are….right like this!” –Inside of your bend arm.)

·         Straight: Measures exactly 180®

·         Obtuse: Measures more than 90® but less than 180® (“Obtuse angels are Ob…tuse!”)

·         Acute: Measures less than 90® (Are oh so cute)

·         Reflex: Mesures between 180® and 360®. (“Reflex angles are…. Outside”)

·         Vertex: The point where 2 rays meet, is always in the middle of the angle name.

·         Vertical: Opposite

·         Adjacent: Next to each other

Special Pairs of Angles:

·         Complimentary: Two angles that create a right (90®) angle

·         Supplementary: Two angles that create a straight (180®) angle.

Parallel Lines: Lines that never intersect, but remain the same distance apart.

Perpendicular lines: Lines that meet at a right angle.

Intersecting Lines: Lines that meet/cross at a point (The point where the two hands meet on a clock in the middle)

Point: Can be represented by a dot.

Line: Passes through 2 points

Line Segment: Starts at point A and ends at point B

Ray: A straight line that begins at an endpoint and goes on forever in a certain direction.

Angle: Two rays with the same end point

Triangle: A figure with three corners and three sides. Every triangle contains three angels. The sum of the angles is always 180®, regardless of the size or shape of the triangle. If you know two of the angles you can subtract them from 180® to find the number of degrees in the third angle.

Types of triangles:

·         Equilateral: A triangle with all three sides equal in length. All three angles than the same measurement.

·         Isosceles: A triangle with at least two sides equal in length, at least two angles have the same measurement.  (A triangle with all three sides the same is an isosceles triangle but is usually called an equilateral triangle)

·         Scalene: A triangle with sides of 3 different lengths, and all three angles have different measurements.

ALL TRIANGLES: The sum of the three interior angles is always 180®

2D shapes: Having length and width but no thickness. Have area but not volume.

Polygons: A 2 dimensional figure that is made up of 3 or more straight lines joined end to end to make one closed figure and the lines may not cross.

Regular Polygon: All the sides are congruent (same).

Quadrilaterals/Quadrangle: A polygon with exactly 4 sides. Examples: Square, rectangle, rhombus, trapezoid. The sum (total) of the measures of the angles in any quadrilateral is 360®

Parallelogram: A quadrilateral with 2 pairs of parallel sides. Opposite sides are congruent (same) and opposite angels have the same measurement.

Rectangle: A figure with four corners and 4 sides 4 right angles. Sides opposite of each other are the same length.

Square: A figure with four corners and four sides

Rhombus: A quadrilateral, parallelogram, every square is a rhombus but not all rhombuses are squares.

Trapezoid: A quadrilateral that has exactly one pair of parallel sides.

3D shapes: Shapes with length, width, and thickness, solid object with area and volume. All points are not in a single plane. They have a face, a side, and a vertex.

“A Face is, a flat surface….. On a 3-D shape!”

Cube: A figure with 6 square faces

”A cube has 6 flat faces, 8 vertices, 12 straight edges, Roll the dice please!”

Prisms: A 3D figure with two identical, parallel bases. (Triangular prism, rectangular prism)

“A rectangular Prims has, 6 flat faces, 8 vertices, 12 straight edges, a tissue box please”

Pyramids: A 3D figure whose base is a polygon and whose faces are triangles, with a common vertex, the point where two rays meet.

“A pyramid… The apex is the place, Where the triangular faces meet! The base is below, It’s the pyramids seat!”

Cones: A 3 dimensional figure with a circular base and a curved surface and one vertex which is called the apex.

“What’s a cone? We end at the top with an apex! A birthday hat, an ice cream cone, Just one vertex!”

Apex: In a pyramid or a cone, the vertex or apex is opposite the base. In a pyramid all the faces meet at the apex.

Cylinders: A 3-dimentional shape that has 2 circular bases that are parallel and congruent and are connected by a curved surface. A soup can is shaped like a cylinder.

”Cylinder…2 curved edges, No vertices, A paper towel roll, or a can of soda please!”

Spheres: Looks like a round ball. Completely curved 3 dimensional shape.

“A sphere has… Just one curved face! A ball, a globe, or a planet in space!”

Polyhedron: A solid 3D shape, all faces are flat and formed by polygons, and there are no curved lines.