Lesson 2: Math is BeautyMPP.7

I can…

I can use bilateral symmetry to describe structure in nature and in human creations.

Key words

• symmetric — Having two halves that match — one side is a mirror image of the other.
• mirror image — A copy of a figure flipped across a line, so the two halves face each other.
• bilateral symmetry — Reflective symmetry in plants and animals — the two sides of the body mirror each other.
• line of symmetry — The line you can draw through a figure so each side is a reflection of the other.
• balance — An even, steady arrangement — neither side feels heavier than the other.

Steps

1. I look at the two sides of the butterfly, and they look like mirror images — the butterfly is symmetric.
2. All butterflies have reflective symmetry. In plants and animals, this is called bilateral symmetry.
3. To show it, I draw a line down the middle of the butterfly's body: everything on the left is reflected on the right.

Try it

Name another animal that has reflective or bilateral symmetry.

Check your answer

Check with your guided notes.

Sentence starter

I know ___ because ___.

Goal: I can describe a symmetric design using the words mirror image, line of symmetry, and balance.