Question 11
Given a quadrilateral \(ABCD\) with \(AB=BC=3\text{ cm}\), \(CD=4\text{ cm}\), \(DA=8\text{ cm}\), and \(\angle DAB+\angle ABC=180^\circ\), calculate its area.
Editorial convention: \(ABCD\) is the ordinary simple convex quadrilateral with vertices in that order.
Editorial convention: \(ABCD\) is the ordinary simple convex quadrilateral with vertices in that order.