Question

Which of the following statements is not true about the figure given below?

• A. $\angle$DBC = 180${}^{\circ }$
• B. $\angle$CBA and $\angle$DBA are supplementary.
• C. $\angle$ABD = 60${}^{\circ }$
• D. $\angle$CBA = 90${}^{\circ }$

Answer 1

The correct option is C

$\angle$ABD = 60${}^{\circ }$

Here $\angle$ABD and $\angle$ABC are supplementary, since they lie on a straight line.
Hence $\angle$DBC = 180${}^{\circ }$
Given, $\angle$ABC = 90${}^{\circ }$
$\therefore \angle$ ABD = 180 - $\angle$ ABC = 180 - 90 = 90${}^{\circ }$