Emerson is completing a construction of an equilateral triangle inscribed in a circle as shown below. what should be the next step in his construction?

I think you should provide a picture of the diagram of the circle. but most of the times, to form an equilateral triangle in a circle, you will have to measure the length of the triangle required using a compasses. then, from a point at the circumference of the circle you should bisect another point in the circumference using your compasses based on the length you measured earlier. then from the bisected point, repeat the steps without changing the measurement of the length of the triangle. later then, you will need to connect all the bisected points using a ruler and label the measurements and youre done. that should be right. good luck. :)