TRIANGLE TYPES

According to their angles and sides, triangles can be classified as:

With this theory will be enough. Do you find it interesting? 

Check this shape and count HOW MANY TRIANGLES are therein?

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TRIANGLES-Definition

A triangle, as you might know, is a geometrical shape (polygon) with three sides. 

Every triangle has three SIDES and three ANGLES.

Those three angles ALWAYS ADD to 180º : (α + β + γ = 180º)

What´s the name of the three sides of this triangle?

___   ___   ___

AB, BC, CA

All sides are segments, but are also called after one small letter,

which is the same than the opposite vertex.

We use then : 

                    ____

c instead of AB,

                     ____

a instead of BC

                ____

and b instead CA .

You have to know also that ANGLES are named after greek letters:

A=α  Β=β  C=γ     (α + β + γ = 180º)

You must know them. That way names and formulas become easier for you, dear students.

Now, some questions for you to discover:

DO YOU KNOW how many triangles do exist?

CAN YOU find examples for triangles IN NATURE? 

...and in HUMAN WORLD? 

IS THERE any triangle with more/less than 180º angles?

SUPPORT-(Reforç) BISECTORS-PARALLELS

Want to BISECT ONLINE? Let´s play this game.

http://www.mangahigh.com/en/maths_games/shape/locus_and_construction/construct_bisectors_and_other_lines

VIDEO: Drawing parallel lines (lefthanded students)

http://www.youtube.com/watch?v=zsln2MCd-UU

VIDEO: Drawing parallel lines(Righthanded students)

http://www.youtube.com/watch?v=pRPa2JGiZL0

OUR MATERIALS

Here´s the list of all materials required:

RULERS: long straight ruler, 45º and 30º-60º set square.
COMPASS: one compass. Please write your name and group on it!
NOTEBOOK: one DIN A-4 notebook (for writing and sketching). It must have WHITE pages.
WORKBOOK: one DIN A-4 workbook (THICK paper). It´s used for definite works (those to be corrected)
PENCILS: one soft (0B, 1B, a.s.o.) and one hard pencil (4H, 5H,a.s.o.)
MARKERS: 0,2-0,4-0,8 mm black markers. (NOT permanent marker)
Some colours you have at home (wax, wooden crayons or markers) are welcome.

You also need a FOLDER to keep your work in. You MUST leave it in the classroom. 
You can leave your tools (compass, rulers…) also. There is a safe place for them.

EVERY MATERIAL MUST HAVE YOUR NAME WRITTEN.