The shortest sides of two similar polygons have lenghts in the ratio 2: 5.
the perimeter of the smaller polygon is 20. the perimeter of the larger polygon is

The pyraminx is a rubik's cube-type toy in the shape of a tetrahedron. the pyraminx shown below has edges 15\,\text{cm}15cm long and vertical height h=12.2\,\text{cm}h=12.2cm. the triangle drawn with dashed lines is a right triangle. what is the distance rr? round your answer to the nearest tenth.