3. let n = {0, 1, ,9, 10} consider a relation r on nx n defined by (a, b) r (x, y) iff a + y = b + x i) prove that r is an equivalence relation. ii) describe the equivalence classes geometrically. iii) describe the quotient set nxn/r. iv) what is the index of r?

Circle a has a diameter of 7 inches, a circumference of 21.98 inches, and an area of 38.465 square inches. the diameter of circle b is 6 inches, the circumference is 18.84 inches, and the area is 28.26 square inches. part a: using the formula for circumference, solve for the value of pi for each circle. (4 points) part b: use the formula for area and solve for the value of pi for each circle. (4 points)