Finding the Pieces – 1
A trapezoid is a four-sided figure that has exactly one pair of parallel sides (parallel lines in a surface are lines that never meet). In the large triangle on the left, there are five triangles marked – the four colored triangles and the entire triangle. The same large triangle on the right has one of its three trapezoids colored in green.
THE CHALLENGE
In each of these three figures, count the number of triangles and trapezoids.
EXPLORATION
Make drawings like these for other people to count the triangles and trapezoids.
Notes
THE CHALLENGE
The square in the upper left has four smaller triangles plus four more triangles made out of pairs of smaller triangles. So it has eight triangles in all. It has no trapezoids in it.
The square in the upper right corner eight triangles in the inside square and eight more in the big square, so 16 triangles in all. It has four trapezoids.
The triangle in the bottom has a total of 12 triangles and six trapezoids.