• # question_answer If the four sides of a quadrilateral ABCD are tangential to a circle, which of the following is true? A)  $\text{AC}+\text{AD}=\text{BD}+\text{CD}$ B)  $\text{AB}+\text{CD}=\text{BC}+\text{AD}$ C)  $\text{AB}+\text{CD}=\text{AC}+\text{BD}$ D)  $~\text{AC}+\text{AD}=\text{BC}+\text{AB}$

Given sides of a quadrilateral ABCD are tangential to a circle. $\therefore$ $\text{7}\times \text{13}+\text{13}$