What is the value of x? in a equation

Fiona and her friends are playing a game by guessing where a coin will land when it is randomly dropped inside the square shown below. fiona guesses that the coin is likely to land in the blue area. which explains whether or not fiona is correct and why?

Abcd is a square. what is the measure of angle bac

Write a linear funtion f with the values f(2)=-1, and f(5)=4