What is the surface area of a rectangular prism with a base length of 7 yd, a base width of 5 yd, and a height of 6 yd?
a.
107 yd2
b.
144 yd2
c.
210 yd2
d.
214 yd2

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.