The problem appears to be the product of a scalar given by r(x=0) and a vector (R(2,0),90°(A)).
Regardless of what the components mean, the scalar should be distributed to each vector component:
(r(x=0)R(2,0),r(x=0)90°(A)), so the given equality is false.
For example, if r(x=0)=3, R(2,0)=4 and 90°(A)=5, the result would be 3(4,5)=(12,15).
90°(A) could be interpreted as the number of right angles in figure A.
r could be a probability function.
R could be a function of two variables, perhaps defining their sum, difference, product, etc.