Simplify (/3). a.) -3 1/3 t b.) s^2t c.) 3s^2t  (if this format is too weird i have added a screenshot) in advance!

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.