Great, you know that. no need to ask more.
The answer is 
*Remember x=
You are technically dividing in this, whenever you divide anything with exponents, you subtract them. 
Therefore, the x's would cancel out, leaving just 
Step-by-step explanation:
p = 2r + pi×r
p = r(2 + pi)
r = p/(2 + pi)
The rays MR and MP intersects at the point M, this means the point M is the vertex of the ∠2.
Another name for ∠2 is ∠PMR.