Help me PLease and no incorrect answers only answer if your sure, Show your work for each one please. And take your time.

The pyramid below was dissected by a horizontal plane which shape describes the pyramid horizontal cross section

What is the measure of sty in oo below? 130 310 230 50

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.