11. ABC and ADC are two right angled triangles with common hypotenuse AC. Prove
that \(\angle{CAD}\) = \(\angle{CBD}\).

Draw a circle with AC as diameter passing through B and D. Join BD.

\(\triangle{ADC}\) and \(\triangle{ABC}\) are right angled triangles with common hypotenuse.

\(\angle{CBD}\) = \(\angle{CAD}\) ...(Since, angles in the same segment are equal)

Hence, proved.