Beacon Lesson Plan Library

The Proof Is in the Picture

Sandra Pickard
Santa Rosa District Schools


Students photograph items that are geometrical figures.They use measurements of item to write a formal or informal proof to prove the item is what they say it is.The proofs are exhanged with other groups; the students must match the proof to the photo.


Uses properties and relationships of geometric shapes to construct formal and informal proofs.

Describes, analyzes and generalizes relationships, patterns, and functions using words, symbols, variables, tables and graphs.

Interprets data that has been collected, organized, and displayed in charts, tables, plots.


-Polaroid camera (instant pictures)
-Picture frame should be the actual size of a Polaroid picture.


1. Obtain permission to leave classroom.
2. Notify front office when you leave the classroom and of your general location on campus.
3. Have enough film on hand for each group and extras.
4. Make copies of worksheets.
5. Obtain and prepare all materials.


1. Students are placed in groups of 3 – 4 (Teacher assigned or free choice)

2. The teacher conducts a review of geometric figures and lists them on the board.(transversals, right triangles, pentagons etc.)

3. Review the operation of the Polaroid camera.

4. Each group selects a figure (no duplicates).

5. The groups are given a picture frame, worksheet and other materials and are sent out to find their figure.

6. When the students have found their figure they take measurements (any necessary) and sight the figure with the picture frame to decide how best to photograph the figure.

7. After the students have found and measured their figure they report back to the teacher for the Polaroid camera and photograph the figure.

8. After photographing the figure the group writes a formal or informal proof of the figure. The students will determine what information to supply as the given.

9. After each group has written a proof the photographs are taped to a wall or board, the proofs (without figure names) are distributed randomly and each group must then identify the figure that goes with the proof.


Assess student knowledge of geometric shapes using the attached rubric.

Attached Files

WORKSHEETS AND RUBRICS     File Extension: pdf

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