Symmetry Lines: Determine the number of symmetry lines a polygon has.
Symmetry Lines II: Find polygons that have line symmetry. Many polygons do not have line symmetry.
Diagonals in a Polygon: Consider the number of diagonals in a triangle, quadrilateral, pentagon, hexagon, heptagon, and octagon.
Round Robin Tournament: Use the sides and diagonals in a regular polygon to create a round robin tournament
N-Sided Circle?: Compare the perimeters of polygons to the circumference of the circle.
Dividing a Trapezoid: Divide a given shape into 4 congruent shapes.
Avoiding a Pentagon: Can you draw points on a piece of paper so that it is not possible to connect them to form a convex pentagon?
Same Size Perimeter: If the perimeter remains the same, can the area change?
Pentagram Triangles: How many triangles are formed?
Perplexing Pentominoes: Explore with pentominoes.
Inscribing & Circumscribing Polygons: Construct polygons using a dynamic geometry software that are inscribed in a circle or circumscribe about a circle.
Submit your idea for an investigation to InterMath.