Answer
Steven is left with 1$\frac{1}{12}$yd of canvas.
Work Step by Step
The length of canvas he has left can be obtained by taking the total initial length and subtracting the length of canvas which he used.
4$\frac{1}{2}$-1$\frac{2}{3}$-1$\frac{3}{4}$=1$\frac{1}{12}$