 Hello and welcome to the session. In this session we discuss the following question which says find the area of the quadrilateral whose vertices are minus 2 to 0 minus 1, 2 0 and 1 1. Suppose we have a quadrilateral with vertices a with coordinates x1, y1, b with coordinates x2, y2, c with coordinates y3 and the vertex b with coordinates x4, y4. The quadrilateral a with cd is given by half into y2, y1, y3 minus x3, y2 plus plus x4, y1, y4, the whole. This is the key idea that we use in this question. We are given the four vertices of the quadrilateral and we are supposed to find the area of this quadrilateral. Suppose we have the vertex a with coordinates minus 2 to b with coordinates 0 minus 1, c with coordinates 2, 0 and b with coordinates 1, 1 minus 2, y1 is minus the y coordinate of point a, 0 that is the x coordinate of b, y2 is minus 1 which is the y coordinate of point b, then point c, y3 is 0 that is the y coordinate of point c, then x4 is 1 which is the x coordinate of point d, y4 is 1 y coordinate of point d. The quadrilateral b cd is equal to minus 1 which is into y1 that is 0 into 2 which is 0 the whole, 0 into 0 that is 0 minus 1 that is minus 2 this whole y3 that is 1 into 0 which is 0 the whole x4 y1 which is 1 into x1, y4 that is minus 2 into the whole is multiplied by 1 upon 2. So, this is going to be equal to half into plus 2, then plus 2 which is equal to half into plus the quadrilateral is equal to this complete cc, I hope you understood the solution of this question.