Transcript Fun with Geometry!!

Fun with Geometry!!
Miss B. Kelley’s 3rd Grade Class
March 2006
Geometry is the study of…
– Shapes
– Lines, rays, and line segments
– Angles
– Area
– Perimeter
– Volume
SHAPES
• Click on the shape below for
more fun and exploration of
geometric SHAPES!
LINES, LINE SEGMENTS & RAYS
• A line has no beginning point or end
point. Imagine it continuing indefinitely
to both directions. We can illustrate that
by little arrows on both ends.
• A line segment has a beginning point
and an end point.
All the sides of this triangle are line
segments.
• A ray has a beginning point but no end
point. Think of sun's rays: they start at
sun and go on forever...
ANGLES
•
What is an angle?
– An angle is made up from two rays that have
the same beginning point. That point is called
the vertex and the two rays are called the sides
of the angle.
Vertex
•
Ray
What is an angle?
– Right Angles equal 90 degrees
– Acute Angles are <90 degrees
– Obtuse Angles are >90 degrees
Have more fun exploring these
angles that exist is space!
CLICK
HERE
WHAT IS AREA?
• Math Book Definition of Area:
the number of square units
needed to cover a region or
figure.
• In more understandable
language…area is how much
of a surface you cover when
you lay a shape down. For
example, when you have
your math book on your desk
you have LESS AREA to work
on because it has been
covered.
PERIMETER
• Have you ever thought about
how far you walked when
you walked around the
outside of your house?
• If you did then you were
trying to find out the
PERIMETER!
Calculate the total of all the
measurements.
5 ft.
2 ft.
3 ft.
3 ft.
2 ft.
2 ft.
2 ft.
5 ft.
(2ft. x 4) + (3 ft. x 2) +(5 ft. x 2)=
(8 ft. + 6 ft.) + 10 ft. =
14 ft. + 10 ft =
The perimeter is 24 ft.
Can you turn up the VOLUME?
• No silly!! The VOLUME in math
isn’t about how loud the music is.
• VOLUME in math is how much
space a 3-dimensional figure
encloses.
– Encloses means to keep in or to hold.
• We would use our one unit cubes
(cubic units) to find our answer.
– You would ask yourself, “How many
cubic units (one unit cubes) would it
take to create a 3-D Rectangle?”
Find the two orange cubes that will
take you to the two games!
How many cubic
units will it take to
fill in this empty
cube?