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 — Both halves match, like a mirror.
• mirror image — A flip of a shape across a line.
• bilateral symmetry — Both halves of a living thing match, like mirror images.
• line of symmetry — A line that cuts a shape into two matching halves.
• balance — Steady and even. No side is heavier.

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.