 Hi and how are you all today? The question says, find the value of the unknown interior angles X in the following figures and the figure which we need to deal with is this. We are given the exterior angle as 100 degrees and one of the interior opposite angle as 70 degree. We need to find out the other interior opposite angle. Now let's start with the solution. We know that sum of interior opposite angles is equal to the exterior angle that is according to exterior angle property of a triangle. Now here we are given the interior opposite angles as 70 degree and X respectively. The sum will be adding them up and it will be equal to the exterior angle which is 100 degree. What we need to do next is we just need to find the value of X that will be 100 degrees and 70 will be transposed from the left hand side to the right hand side. The sign will get changed and from positive it will be negative. This further implies X is equal to 30 degrees. So X is equal to 30 degrees is the required answer to the given question. Hope you understood the solution well and enjoyed it. Do have a nice day.