State if the three numbers can be the measures of the sides of a triangle: 10,20,10 7,7,8 7,11,6 9,2,8

Consider symmetrically placed rectangular insulators with uniformly charged distributions of equal magnitude as shown. x y −−−−−− what is the direction of the net field at the origin?

When are two distinct non vertical lines parallel

James adds two numbers a + b. sally adds the same two numbers but reverse the order b + a what property of addition assures us that james and sally will get the same sum