Triangle ABC, ab = 4, angle a = 60, angle B = 75, area

Triangle ABC, ab = 4, angle a = 60, angle B = 75, area

If B is used as BD and AC is perpendicular to D, then ad = 2 and BD = 2 (root 3)
CD = BD = 2 (root 3)
Area = 1 / 2 * (2 + 2 radical 3) * 2 (radical 3)
=2 (radical 3) + 6