Construct An Obtuse Angle And Draw Its Bisector. You need only the drawing compass not a protractor since you do not need to know the actual measurement of the angle to bisect it. To bisect an angle means that we divide the angle into two equal congruent parts without actually measuring the angle.
This Euclidean construction works by creating two congruent triangles. Label the points of intersection A and B. Put the compass point on point X and draw an arc that intersects the vertex Q.
Method The construction starts by extending the chosen side of the triangle in both directions.
Label the intersection A. Draw its two chords AB and CD such that AB is not parallel to CD. Put the compass point on vertex Q. See the proof below for more on this.
