Consider the following sets. cap u is equal to all triangles cap e is equal to x divides x is in cap u and x is equilateral cap i is equal to x divides x is in cap u and x is isosceles cap s is equal to x divides x is in cap u and x is scalene cap A is equal to x divides x is in cap u and x is acute cap o is equal to x divides x is in cap u and x is obtuse cap r is equal to x divides x is in cap u and x is right Which is a subset of cap i ?