 Hi and welcome to the session. Let us discuss the following question. Question says, given a parallelogram ABCD, complete each statement along with the definition of property used. Let us now start with the solution. Consider first part of the given question. We have to find AD is equal to which side of the parallelogram ABCD. Now according to the property of a parallelogram, the opposite sides of a parallelogram are equal, so AD is equal to BC. So here we can write AD is equal to BC since opposite sides of a parallelogram are of equal length. Now consider second part of the given question. We have to find angle DCB is equal to which angle. Now first of all let us talk angle DCB in the given figure. This is angle DCB. Now opposite angle property of a parallelogram states that measure of opposite angles of a parallelogram are equal. So we get angle DCB is equal to angle DAV since opposite angles of a parallelogram are of equal measure. Now consider third part of the given question. Here we have to find OC is equal to what? Clearly you can see O is the point of intersection of two diagonals BD and AC. And diagonal property of a parallelogram states that diagonals of a parallelogram bisect each other. That is OC is equal to OA and OD is equal to OV. So we can write OC is equal to OA since diagonals of a parallelogram bisect each other. Now in the fourth part we have to find the sum of these two angles. First of all let us mark this angle in this figure. Angle DAB is this angle and angle CDA is this angle. Now clearly you can see these are two adjacent angles of parallelogram ABCD. Property of parallelogram states that the adjacent angles in a parallelogram are supplementary. So sum of these two angles is equal to 180 degrees since the adjacent angles in a parallelogram are supplementary. You can find the sum of these two angles other way also. Clearly you can see DC is parallel to AB since opposite sides of a parallelogram are parallel to each other. So DC is parallel to AB and DA is transversal. And this angle and this angle are coincident angles on same side of the transversal DA. So their sum must be equal to 180 degrees. So this is our required answer for the given question. This completes the session. Hope you understood the solution. Take care and keep smiling.