Triangle or not?

This task is about identifying whether some shapes are triangles and what makes them triangles.

Question

Three children are talking about whether shapes are triangles or not.
 
tom-boy-face-100.png possible triangle
a)  Tom says this is not a triangle.
     What do you think?

    • It's a triangle.

    • It's not a triangle.

Explain why you think this.

Question

sarai-smaller.png possible triangle
b)  Sarai says this is not a triangle.
     What do you think?

    • It's a triangle.

    • It's not a triangle.

Explain why you think this.

Question

boy-face-flattop-smaller.png  possible triangle
c)  Tyler says this is not a triangle.
     What do you think?

    • It's a triangle.

    • It's not a triangle.

Explain why you think this.

Question

d)  Select all the shapes below that are triangles.

    • possible triangle

    • possible triangle

    • possible triangle

    • possible triangle

    • possible triangle

    • possible triangle

    • possible triangle

    •  
      triangle-8b.png

    • possible triangle

Question 1Change answer

possible triangles

e)  Describe how you know a shape is a triangle.