Friday, November 20, 2009

Geometry Test

TGIF, Grade 5s!

Today, I gave you your study sheets for Tuesday's test on our recent geometry unit.  Here's what the study sheet said:

We will be having a test on what we’ve been learning about whole numbers. Our test will be on Tuesday, November 24th.
Make sure you know how to:

• name triangles based on the length of their sides (e.g., equilateral, isosceles, scalene)

• name triangles based on their angles (e.g., right angle triangle, obtuse triangle, acute triangle)

• measure the angles of triangles with the use of a protractor

• draw an angle when given a measure (e.g., draw a 45° angle)

• construct a triangle given measurements of sides and/or angles (e.g., construct triangle ABC, with angle A measuring 25°, angle B measuring 80°, and the length of AB measuring 42mm)

• recognize which net creates which 3D solid

• create a net for a 3D solid (e.g., make a net for a triangular prism)

Are YOU ready?
 
Have a great weekend!
 
-Ms. Lewis.

Monday, November 16, 2009

Constructing Nets

Hi Grade 5s,


Today in class we talked about nets. Remember that to create a net, we need to find out how many faces a figure has, and what shape those faces are.
For example, I could make a net of this pentagonal prism:





First, I would count the faces and find that there are 7 faces (2 bases, 5 faces around). 5 of those faces are rectangles, and the other two faces are pentagons.

The net would look this this:



Find a solid figure around your house. See if you can figure out how you could create it with a net. Prize tomorrow for whoever posts their net here first.

Yay nets!
-Ms. Lewis.

Monday, November 9, 2009

Naming and Sorting Polygons by Angles

Happy Monday!

Today in class we began to talk about how to name triangles based on their angles.  We remembered that:
  • right angles are 90°
  • acute angles are less than 90°
  • obtuse angles are greater than 90°
We learned that we can measure the three angles (tri-angle...remember?) of a triangle to determine whether it is a right angle triangle, an acute angle triangle, or an obtuse angle triangle.  The rule is:
  • right angle triangles have one 90° angle
  • acute angle triangles have all 3 angles less than 90°
  • obtuse angle triangles have one angle greater than 90°
Remember: you can only have an acute triangle if all 3 angles are less than 90°.

Regular polygons are polygons (closed shape, at least 3 sides) that have all sides the same length, and all equal angles.  Irregular polygons have sides of different lengths, and different angles.

SUPER TERRIFIC BRAIN-BUSTING QUESTION:
WHAT KIND OF TRIANGLE IS A REGULAR POLYGON?  EXPLAIN YOUR ANSWER!
(First person to post the answer on the blog wins a prize in class tomorrow!)

See you tomorrow!

-Ms. Lewis.

Thursday, November 5, 2009

Measuring Angles

Hi Grade 5s,


Today we began measuring angles using protractors. Don't worry if you're still trying to get the hang of it--it takes practice and patience.

I found a great interactive activity at mathisfun.com where you can use a virtual protractor to measure angles.

Try it out!

http://www.mathsisfun.com/geometry/protractor-using.html
-Ms. Lewis.

Tuesday, November 3, 2009

Geometry Definitions

Hello you lovely learners!

For homework tonight, you had to find the definitions for the following geometry terms:
  • equilateral triangle
  • isosceles triangle
  • scalene triangle
  • pentagon
  • hexagon
  • octagon
  • parallelogram
  • trapezoid
You can post your definitions straight to the blog as a comment, if you like.  Just remember to include your name.

See you tomorrow!

-Ms. Lewis.

Monday, November 2, 2009

Triangles, Triangles, Triangles!

Happy Monday!

Today, we began our geometry unit by looking at the 3 different kinds of triangles: equilateral, isosceles, and scalene. 

Let's take a closer look at each:

Equilateral - We recognized that the word "equilateral" sounds a lot like "equal", which means the same.  We are so smart that we figured out that an equilateral triangle is a triangle with all 3 sides the same length.




Isosceles (eye-saw-so-leez) - We learned that an isosceles triangle is one with two sides that are the same length.




Scalene (skay-leen) - We figured that if an equilateral had 3 sides of the same length, and an isosceles had 2 sides of the same length, then a scalene triangle must have 3 sides of different lengths



We're so smart...

See you tomorrow!

-Ms. Lewis.