I would insert the NRICH at the end of my lesson to reinforce the lesson and check their knowledge. This would be used to wrap up everything just taught by giving them a fun way to practice and really use their new skills.
They are to follow the game or activity identified by me on the website.
A complicated picture with tons of different shapes and lines is given to the students. They are then suppose to look for the triangles throughout the picture and color them in.
Color in the triangles shown in the hand-out.
3 Direct Instruction
Here I would include notes and specific details about each different type of triangle and their properties.
The student would take notes in his or her spiral.
4 Guided Practice
Using this game http://nrich.maths.org/5638 I could have the students reinforce the different triangles we just discussed in class. We would double check and go over which one goes where and why.
Separate out the three different kinds of triangles into groups. Once they're done some will be called on to explain their reasoning.
5 Independent Practice
This site is great for testing what the students have learned.
The students are directed to the review related to triangle identificiation.