What is number 11 i think i'm doing it wrong

How can we find the measure of an exterior angle if we know the measurement of an interior angle

Can someone me i’m confused. will give brainliest and a whole bunch of points

The ksp expression for the system pbcl2(s) pb+2(aq) + 2 cl-(aq) is: [pbc12][pb+2][2cl-] [pb+2][cl-]2 [pb+2][2cl-]2 [pbcl2][pb+2][cl-]2 [pb+2][2cl-]2[pbcl2]