This book is in collaboration with students. They also applied triangles to measure the height of some monuments.

1. Measure a student's height (use the string).

2. Measure the length of the student's shadow (use the string).

3. Measure the length of the shade of a tree (use string).

4. Use pencil and paper to determine the proportion and solve the height of the tree (draw the picture).

5. Switch jobs and repeat using another shaft.

6. Return to class and work in groups to complete group information written representation.

Sîrghi Gabriela

Mirror method: