Please tell how to solve Q 14.

Dear Student ,

Given AB = AC, BD ⊥ AC From right △ ADB, By pythagoras theorem, {AB}^{2} = {AD}^{2} + {BD}^{2} ⟹ {AC}^{2} = {AD}^{2} + {BD}^{2} [∵ AB = AC] ⟹ {(AD + CD)}^{2} = {AD}^{2} + {BD}^{2} ⟹ {AD}^{2} + 2 \times CD \times AD + {CD}^{2} = {AD}^{2} + {BD}^{2} ⟹ {BD}^{2} - {CD}^{2} = 2 \times CD \times AD Hence, proved

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