Cogito
Grade 2 Math · Chapter 8 · Lesson 3
Shapes by Their Sides
Triangles, quadrilaterals, pentagons, and hexagons.
10 problems · about 12 minutes · 2.G.A.1
What this lesson teaches
The child names and draws shapes with a given number of sides or angles.
- The number of straight sides names a shape.
- Quadrilateral means any shape with 4 sides.
- 5 sides is a pentagon, 6 is a hexagon.
Warm-Up Review
From earlier lessons. Loosen up before the new work.
2 problemsReview — A.M. and P.M.: Is 3 o’clock in the afternoon a.m. or p.m.?
Answer p.m.
Why Afternoon times are p.m.
Review — Time to Five Minutes: The long hand is on the 5. How many minutes past?
Answer 25
Why The 5 means 25 minutes.
Warm Up
Straightforward practice. Get the method working first.
4 problemsA shape has 6 straight sides. What is it?
Answer A hexagon.
Why 6 sides makes a hexagon.
How many sides does a quadrilateral have?
Answer 4
Why All quadrilaterals have 4 sides.
How many sides does a pentagon have?
Answer 5
Why One more than a quadrilateral.
How many sides does a quadrilateral have?
Answer 4
Why Same as a square.
Build It Up
The same ideas with more to keep track of.
2 problemsHow many corners does a hexagon have?
Answer 6
Why Same as its sides.
How many sides does a triangle have?
Answer 3
Why The smallest number that closes a shape.
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
2 problemsNaming Shapes: A shape has 5 straight sides. What is it?
Answer A pentagon.
Why 5 sides makes a pentagon.
The Family: Is a square a quadrilateral?
Answer Yes. It has 4 sides.
Why Any 4-sided shape is a quadrilateral, including squares.