Geometry Slideshow

POINT A point is an exact location in space. A Say “POINT A”

LINE A line is a straight path of points that goes on and on in two directions. A B Write Say “LINE AB” A B

LINE SEGMENT A line segment is a part of a line. It has two endpoints. A B Write Say “LINE SEGMENT AB” A B

RAY A ray is part of a line. It has one endpoint and continues on and on in only one direction. F G Write Say “RAY FG” F G

ANGLE An angle is formed by two rays that have the same endpoint. The common endpoint is the vertex. B A C SAY: 1)”Angle A” (vertex) 2) “Angle BAC” 3)”Angle CAB” Write A BAC CAB

ANGLE B A A BAC C CAB Write QUESTION: WHY CAN’T WE CALL THIS ANGLE CBA or BCA? ANSWER: The VERTEX letter must always be in the center when naming angles OR just by itself. B A Write A BAC C CAB

PARALLEL LINES Never intersect (cross) They are like the sides of a street Parallel lines will never meet each other, no matter how much you continue them in either direction.

INTERSECTING LINES Pass through the same point

PERPENDICULAR LINES Lines that intersect and form 4 right angles. The little symbol marked in the corner means “right angle.”

RIGHT ANGLE Measures 90 degrees has a square corner

ACUTE ANGLE Measures less than a right angle (90 degrees) It’s so cute! (Get it? Tiny? Acute?)

OBTUSE ANGLE Measures more than a right angle (90 degrees) Less than 180 degrees *Tubas are big and so are obtuse angles!

STRAIGHT ANGLE Measures 180 degrees

POLYGONS Closed, flat plane figures with 3 or more lines segments Is a circle a polygon? NO!

TRIANGLE 3 sides, 3 vertices Right triangle

QUADRILATERAL 4 sides, 4 vertices Square Rectangle Trapezoid Parallelogram Rhombus

QUADRILATERAL Square: all sides are equal Rectangle: Trapezoid: has 4 right angles, 2 sets of parallel lines Trapezoid: One set of parallel lines, one set of lines that will intersect Rhombus: Slanted square Parallelogram:Slanted rectangle, opposite sides are parallel

PENTAGON 5 sides, 5 vertices

HEXAGON 6 sides, 6 vertices

HEPTGON 7 sides, 7 vertices

OCTAGON 8 sides, 8 vertices

NONAGON 9 sides, 9 vertices

DECAGON 10 sides, 10 vertices

3D shapes