Quadrilaterals

Triangles Recap

-Sum of all angles= 180
-3 vertices
-3 sides
-regular angle =60 degees
-2 short sides have to be bigger than the longest side
-exterior sum of the angle is 360 degrees


Exploring Quadrilaterals



Side Lengths             Does it make a unique Quad.                  Sketch
1. 6, 10, 15, 15
2. 3,5,10,20
3. 8,8,10,10
4. 12,20,6,9

*Can't make a unique quad. because too flexible. 
*We decided to add a piece in the middle for stability (diagonal) 
*Creates triangles which are more stable shapes

Where do we see triangles in our everyday lives?
-Construction (saw: 2 ends are triangles, stable enough to hold pieces of wood)
-Buildings, roofs
-Tips of a saw, ridges

2 Big ideas about Quadrilaterals:

1) Can't make a unique quad. because too flexible. We decided to add a piece in the middle for stability (diagonal). It creates triangles which are more stable shapes

2)  3 smaller sides need to be greater then the biggest side