A dumpling can be made from dough shaped like trapezoids. Which statement is true? STUV is not an isosceles trapezoid. \begin{tabular}{l} STUV is an isosceles trapezoid because \\ \( T U \cong U V \). \\ STUV is an isosceles trapezoid because \\ \( \angle S T U \) and \( \angle V S T \) are supplementary. \\ \( \begin{array}{ll}S T U V \text { is an isosceles trapezoid because } \\ S U \cong T V \text {. } \\ U V=2.5 \mathrm{~cm} \\ V S=1.8 \mathrm{~cm} \\ S U=3 \mathrm{~cm} \\ T V=3.3 \mathrm{~cm} \\ m \angle S T U=81^{\circ} \\ m \angle V S T=99^{\circ}\end{array} \) \\ \hline\end{tabular}

To determine whether STUV is an isosceles trapezoid, we need to check the trapezoid's properties. An isosceles trapezoid has one pair of parallel sides and the non-parallel sides (legs) are of equal length. The angles on each side of the trapezoid should also be supplementary as you can see here, \(\angle S T U + \angle V S T = 81^{\circ} + 99^{\circ} = 180^{\circ}\). However, upon closer inspection of the side lengths \(SU\) and \(TV\), they are not equal (\(3 \, \text{cm} \neq 3.3 \, \text{cm}\)). Therefore, \(STUV\) is not an isosceles trapezoid. For real-life applications, understanding trapezoids is crucial, particularly in architecture and engineering. They appear in bridge designs, where trapezoidal shapes can help evenly distribute weight and stress. This makes structures not only visually appealing but more stable! So next time you see a bridge, remember it might just have a strong and stylish trapezoidal frame!