2-min Fluency Warm-up — How many sides does each shape have? Answer fast!
A triangle has sides.
A square has sides.
A rectangle has sides.
A circle has sides.
Every flat shape has three things we can count:
• Sides — the straight lines
• Vertices — the corners where two sides meet (one is called a vertex)
• Angles — the openings inside each corner
A triangle has 3 sides, 3 vertices, and 3 angles. Sides, vertices, and angles always match!
Count the sides and vertices. Touch each side with your pencil as you count! (Careful: the circle is tricky.)
| Shape | Picture | Sides | Vertices |
|---|---|---|---|
| Triangle | |||
| Square | |||
| Rectangle | |||
| Star | |||
| Circle |
Number Talk — Explain WITHOUT counting.
A shape has 5 vertices. Without drawing it, how many sides must it have? How do you know?
My thinking:
Can a shape have 4 sides but only 3 vertices? Explain why or why not.
My thinking:
Read carefully. Draw a picture to help!
Maria is making a garden bed shaped like a triangle. She puts one fence post at every vertex and one flower in the middle of every side. How many fence posts and how many flowers does she need in all?
Draw your thinking:
Posts: Flowers: Total: