Question

There are 3 shapes inside a box. Together they have 3 sides. What can be the possible shapes?

• A. 2 circles, 1 triangle
• B. 1 circle, 2 triangles
• C. 3 circles
• D. 3 triangles

Answer 1

The correct option is A 2 circles, 1 triangle

$\text{Say:}$Let’s read the question.

$\text{Ask:}$
$\bullet$ Since there are 3 shapes and together they have 3 sides, do you think each shape has only 1 side? Why?
Ans: No, because a closed shape with only 1 side cannot be formed.

$\bullet$ Do you know any closed shape with 2 sides?
Ans: No, there are none.

$\bullet$ Which shape has 3 sides?
Ans: Triangle

$\bullet$ Do you think the box has 3 triangles? Why?
Ans: A triangle has 3 sides. So, 3 triangles together will make 3 + 3 + 3 = 9 sides in all. But the shapes in the box have 3 sides in all. Therefore, it cannot have 3 triangles.

$\bullet$ Can option B be the possible shapes in the basket? Why?
Ans: No, because a circle has 0 sides, but a triangle has 3 sides. So 2 triangles and 1 circle will have 0 + 3 + 3 = 6 sides in all.

$\bullet$ Can option C be the possible shapes in the basket? Why?
Ans: Yes, because 2 circles and 1 triangle will have only 3 sides in all, as circles have no sides.

$\bullet$ If the box has 3 circles, how many sides will be there in all?
Ans: There will be 0 sides in all if all 3 shapes are circles.

Hence, option C is the correct answer.

$\text{WB:}$If required, use the whiteboard to draw shapes, write the number of sides and find the total number of sides as shown.