Question

Question 90
Fill in the blanks to make the statements true.
In trapezium ABCD with $AB\parallel CD$, if $\angle A={100}^{\circ }$, then $\angle D=$ ___.

Answer 1

${80}^{\circ }$

In a trapezium, we know that the angles on either side of the base are supplementary.
So, in trapezium ABCD, given $AB\parallel CD$
$\therefore \angle A+\angle D={180}^{\circ }\Rightarrow {100}^{\circ }+\angle D={180}^{\circ }\Rightarrow \angle D={180}^{\circ }-{100}^{\circ }\therefore \angle D={80}^{\circ }$.