Question

In a trapezium $\mathrm{ABCD}$ with $\mathrm{AB}\parallel \mathrm{CD}$ if $\angle A=100°$ then find $\angle \mathrm{D}$.

Answer 1

Calculate the $\angle \mathrm{D}$.

In the question, it is given that in a trapezium $\mathrm{ABCD}$ with $\mathrm{AB}\parallel \mathrm{CD}$ if $\angle A=100°$.

By using the property of trapezium that the adjacent angle of a trapezium of non-parallel sides are supplementary.

$$\begin{gathered} \angle \mathrm{A}+\angle \mathrm{D}=180° \\ \Rightarrow \angle \mathrm{D}=180°-100° \\ \Rightarrow \angle \mathrm{D}=80° \end{gathered}$$

Hence the value of $\angle \mathrm{D}$ is $80°$.