I will give brainiest to whoever answers correctly !!

What is the value of x in the diagram below?

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.

Find the amount of simple interest earned for depositing the given principle in an account if $2200 is invested at 5.5 % for 6 months