 Hi and welcome to the session I am Asha and I am going to help you with the following question which says in figure 5.10 if AC is equal to BD then close that AB is equal to CD. So, let us begin with the solution and the following figure we are given AC is equal to BD also from the figure we find that AC can be written as AB plus BC since point B lies between A and C. BD can be written as BC plus CD since point C lies between B and T that is AC is equal to AB plus BC and BD is equal to BC plus CD. So, let us number the given equation as 1, this equation as 2 and BD is equal to BC plus CD as third equation and now on substituting and 3 in 1 we get in place of AC we will write AB plus BC and in place of BD we will write BC plus CD. Now subtracting BC from both the sides we get AB plus BC minus BC is equal to BC plus CD minus BC which implies AB is equal to CD subtracting equals from equals. This completes the solution hope you enjoyed it take care and bye for now.