Question

Martha is constructing the circumscribed circle for△RST. She has already used her compass and straightedge to complete the part of the construction shown in the figure.
Which construction could be her next step?

Answer 1

For a better understanding of the question please find the diagram in the file that has been attached. This diagram tells us till where Martha has completed here construction.

As we can see there is an intersection point of AB and CD. That point is of utmost importance to Martha. She will now place the point of the compass on the intersection of AB and CD and extend the compasses to point R, or to point S, to point T, as all are equidistant.

Martha will then draw a circle with center at the intersection of AB and CD and the radius as any of the three distances, which will make the circle pass through the points, R, S and T.

Answer 2

Place the point of the compass on the intersection of AB and CD and extend the compasses to point R.