Free points and brainlist. ​

Find the percent error of the measurement 4 cm

(-y to the power of 2 - 4y- to the power of 2 -6 y +3)

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.