Geometry Homework help??

[janette]

My 11yo DD is doing homework and has this question. She doesn't have a protractor here at the house and I don't know how to solve it without one. Can someone help??

Julie wants to draw a triangle. She knows that one angle is 70 degrees and aother is 55 degrees. How many degrees should the third angle be? How would you classify the triangle(isosceles, scalene or equalteral)?

 

[DonnaS]

The sum of the angles of a triangle are always 180.

So the other angle is 55 degrees.

Edited to add that is therefore isosceles.

 

[cindy_k]

In a Triangle the 3 angles have to add up to 180 degrees.

So 70 + 55 = 125
180 - 125 = 55 <- that's the answer for the third angle

It's an Isosceles.

I got the following from:
http://mathworld.wolfram.com/IsoscelesTriangle.html
Isosceles -
A triangle with (at least) two equal sides (and two equal angles). The name derives from the Greek iso (same) and skelos (leg). A triangle with all sides equal is called an equilateral triangle, and a triangle with no sides equal is called a scalene triangle. The equilateral triangle is therefore a special case of an isosceles triangle having not just two, but all three sides equal. Another special case of an isosceles triangle is the isosceles right triangle.

Have fun!
Cindy in NY

 

[janette]

thanks She missed some classes this week and I'm no help at all!

 

[Pin Wizard]

I recently found a great website. Shhhhhhhhhhhhhhhh, don't tell your DD, but you might find it helpful.

http://school.discovery.com/homeworkhelp/webmath/

 

[Mskanga]

You can ask me about anything , just don't ask about Math! Thanks Pin Wizzard for such a great site, I bookmarked it for when I need it , DD is also doing Geometry and although she doesn't have that many questions, she does every now and then.