Which equation can be used to solve for m angle 1 ?
A
m angle 1 is equal to 1 half times open paren c plus d close parenB
m angle 1 is equal to 1 half times open paren c minus d close parenC
m angle 1 is equal to 1 half times open paren A minus b close parenD
m angle 1 is equal to 1 half times open paren A plus b close paren