Ted is constructing an equilateral triangle. he draws a segment with his straightedge and labels the endpoints a and b. he then puts the compass point on a, opens the compass until the pencil point is on b, and draws a circle.

which move is a correct next step for ted?

keep the same compass opening, place the compass at the midpoint of the segment, and draw a circle.

widen the compass opening, place the compass point on b, and draw a circle.

keep the same compass opening, place the compass point on b, and draw a circle.

shorten the compass opening, place the compass point on b, and draw two arcs that intersect the circle.