Question 12 Marks
In the given figure, if $\angle\text{BAC}=60^\circ$ and $\angle\text{BCA}=20^\circ,$ find $\angle\text{ADC}.$
Answer
View full question & answer→Using angle sum property in $\triangle\text{ABC}, $
$\angle\text{B}=180^\circ-(60^\circ+20^\circ)=100^\circ$ In cyclic quadrilateral $ABCD$,
we have: $\angle\text{B}+\angle\text{C}=180^\circ$
$\angle\text{D}=180^\circ-100^\circ=80^\circ$
$\angle\text{B}=180^\circ-(60^\circ+20^\circ)=100^\circ$ In cyclic quadrilateral $ABCD$,
we have: $\angle\text{B}+\angle\text{C}=180^\circ$
$\angle\text{D}=180^\circ-100^\circ=80^\circ$
