Geometry Slideshow

POINT• A point is an exact location in space.

• Say “POINT A”

LINE• A line is a straight path of points that

goes on and on in two directions.

• Say “LINE AB” • Write

LINE SEGMENT• A line segment is a part of a line.

It has two endpoints.

• Say “LINE SEGMENT AB” • Write

RAY• A ray is part of a line. It has one

endpoint and continues on and on in only one direction.

• Say “RAY FG” • Write

ANGLE• An angle is formed by two rays

that have the same endpoint. The common endpoint is the vertex.

SAY: • 1)”Angle A” (vertex)• 2) “Angle BAC”• 3)”Angle CAB”

• Write

ANGLE• 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.

• Write

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? Acutecute?)

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

Rhombus

Rectangle

Parallelogram

Trapezoid

QUADRILATERAL

Square: all sides are equal

Rhombus:

Slanted square

Rectangle:has 4 right angles, 2 sets of parallel lines

Parallelogram:Slanted rectangle, opposite sides are parallel

Trapezoid:One set of parallel lines, one set of lines that will intersect

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