Alert!

Hello, reader! If you intend to post a link to this blog on Twitter, be aware that for utterly mysterious reasons, Twitter thinks this blog is spam, and will prevent you from linking to it. Here's a workaround: change the .com in the address to .ca. I call it the "Maple Leaf Loophole." And thanks for sharing!

Thursday, November 8, 2012

Benefit from My Hours of Frustration

HERE.

There are some questions below to go with it that don't suck. No further comment. I am so sick of this lesson.


Open the Geogebra File Triangle Inequalities.ggb. (Follow the link from Edmodo, or go directly to http://www.geogebratube.org/student/m21418) You can use the sliders to change the lengths of two of the sides. You can also change the position of two of the segment endpoints. Side AB will always measure 10. Use the sliders to generate four different sets of side lengths: two that can form a triangle (you will know for sure if it turns purple,) and two that can not form a triangle.
AB
BC
AC
Can a triangle be formed?
10



10



10



10





1 Using the given lengths of AB and BC below, find the shortest possible integer length of AC, and the longest possible length of BC.


AB
BC
Shortest possible AC
Longest possible AC


10
3




10
5




10
1




10
14

(conjecture)


x
y




Answer this question without using Geogebra. I have three pieces of wood. The pieces measure 4 cm, 9 cm, and 11 cm. My friend has three other pieces that measure 5 inches, 8 inches, and 2 inches. Will we each be able to create a triangle? Why or why not?

4 comments:

  1. Like manna from blog-heaven, and perfect timing too. Thank you so much for putting in the time on this. You rock!

    ReplyDelete
  2. THANKS for creating this; your GeoGebra skills are appreciated! Seeing it this way reinforces the relationships in a much better way than what students see with linguine. They can make the craziest triangles with pasta.

    ReplyDelete
  3. I haven't used this since last year, but here's my version if you're not totally sick of the lesson :)

    http://scottfarrar.com/geom2011/day3/triangleineq00.html

    ReplyDelete

Hi! I will have to approve this before it shows up. Cuz yo those spammers are crafty like ice is cold.