Properties of Shape - Triangle Activity - Presentation

The lesson on triangles begins with an engaging discussion on their properties and how they differ from squares. Students are encouraged to explore various shapes and identify the odd ones out, prompting them to think critically about the characteristics that define different geometric figures. For instance, they compare 2-D and 3-D shapes, noting that a cube, as a 3-D shape, stands out amongst 2-D shapes. Further activities challenge students to discern shapes based on the number of straight sides, whether they are closed or open, and the number of vertices, reinforcing their understanding of triangles and other polygons.

Students are then introduced to the concept of polygons, identifying them as 2-D shapes with straight sides that are closed. An interactive exercise using lolly sticks helps them visualize and create various polygons, encouraging them to reason and experiment with the shapes they can construct. In subsequent activities, students examine groups of shapes to determine which ones are triangles, based on having three straight sides, three vertices, and being a closed 2-D shape. The lesson concludes with reasoning challenges that ask students to draw different triangles on a 3 by 3 grid and consider how many new triangles could be created on a 4 by 4 grid, with the aid of a geoboard and elastic bands to facilitate their learning.