Luas segiempat tali busur ABCD pada gambar di bawah ini adalah ....
12(ab+cd)sin2θ\frac{1}{2}\left(ab+cd\right)\sin2\theta21(ab+cd)sin2θ
14(ab+cd)sinθ\frac{1}{4}\left(ab+cd\right)\sin\theta41(ab+cd)sinθ
13(2ab+cd)sinθ\frac{1}{3}\left(2ab+cd\right)\sin\theta31(2ab+cd)sinθ
12(ab+cd)sinθ\frac{1}{2}\left(ab+cd\right)\sin\theta21(ab+cd)sinθ
15(ab+2cd)sin3θ\frac{1}{5}\left(ab+2cd\right)\sin3\theta51(ab+2cd)sin3θ