Hello take my points and dont ask y

Steve wants to develop a way to find the total cost of any item including sales tax. the sales tax in his city is 6%. his friend jenna writes the expression x + 6x where x is the cost of the item. explain whether her expression is correct based on the situation.

Does the point (1, sqrt 7) lie on circle shown.

Choose the more precise measurement. 26.4 cm or 8.39 cm