What's is this I do find it out

Which of the following represents the length of a diagonal of this trapezoid?

1) your friend taylor missed class today and needs some identifying solutions of systems. explain to taylor where to find the solution(s) of any system using its graph 2)taylor graphs the following in desmos and decides that f(x) = g(x) at x = 0, x = 1, & x = 3. f(x) = 2x+1g(x) = 2x2+1 provide taylor some feedback that explains which part of the answer was incorrect and why.

Ineed with question three. i don't understand how i'm supposed to achieve 3 marks.