Construct an angle congruent to a given angle.

1. To draw an angle congruent to ÐA, begin by drawing a ray with endpoint D.

2. Place the compass on point A and draw an arc across both sides of the angle. Without changing the compass radius, place the compass on point D and draw a long arc crossing the ray. Label the three intersection points as shown.

3. Set the compass so that its radius is BC. Place the compass on point E and draw an arc intersecting the one drawn in the previous step. Label the intersection point F.

4. Use the straightedge to draw ray DF.

ÐEDF @ ÐBAC

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