If the coefficient of determination is 0.81 the coefficient of correlation?

Given co-efficient of determination, r2 = 0.81.

co-efficient of correlation, r = square root of 0.81

= +0.9, if the data have move in the same direction.(Let x and y as variables then x and y have linear relationship and x increase or decrease and y also have increase or decrease)

= -0.9, if the data have move in the opposite direction.(Let x and y as variables then x and y have linear relationship and x decrease or increase and y is also increase or decrease)