The instructor:

• Draws on a whiteboard or big piece of paper a large version of A.
• Adds the back fin as a right triangle asks children to tell its shape.
• Repeats for the second back fin as an obtuse triangle.
• Repeats for the tail fin as an acute triangle.
• Repeats for the anal fin as a right triangle.
• Repeats for the ventral fin as an acute triangle.
• Repeats for the breast fin as an obtuse triangle.
• Repeats for the head as an acute triangle.

The instructor next:

• Asks children to study the landscape image.
• Tells children the picture is composed entirely of triangles.
• Asks children to point out as many different triangles as possible.
• Asks children to point to an acute triangle, an obtuse triangle, a right triangle.
• Asks children to name the shape of the lake, the distant mountain, the land on the right, the land on the left, and the trees on the left.