Draw a triangle. Easy ... Popularly used on guitar picks and trail route signs, this curvaceous triangle-like shape is named after German engineer Franz Reuleaux. For more details, skip to ...

Draw the square 4 cm by 4 cm base and attach the four congruent isosceles triangles with base 4 cm and height 6 cm on each side of the square. The net is complete. For a solid 3D shape ...