What’s the answer to this i’m confused

How do you use the additive inverse to evaluate an expression that uses subtraction in a full sentence

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.

1- how are translations represented as a function? . . 2- what is the relationship between a translation and a rigid motion? answer my grade depends on it! you so much