Alex is constructing a square in which two of its vertices are points x and y. he has already used his straightedge and compass to construct the lines and arcs shown. what should alex do for his next step? a. use a straightedge to draw a horizontal line that contains point z. b. place the point of the compass on point x and draw any arc above it. c. use a straightedge to draw xz¯¯¯¯¯ . d. place the point of the compass on point y and draw an arc that intersects yz¯¯¯¯¯ , using xy as the width of the opening of the compass.