This PowerPoint slideshow has 23 geometric challenges to help students with estimating: 8 slides explain about corners and edges, the “tri” in triangle, and the types of triangles (equilateral, isosceles, scalene or a right triangle)13 slides give students a chance to count the triangles in overlapping configurations, 10 more slides increase the complexity and difficulty level 10 final challenges give your students a chance to apply what they’ve learned by comparing two problems side-by-side,