(i) Let r and d be the radius and diameter of the circle, respectively.
d = 2r
(ii) Let l and b be the length and breadth of the rectangle, respectively.
Area of rectangle = lb
(iii) Let s, c and p be the selling price, cost price and profit, respectively.
s = c + p
(iv) Let T, p and i be the total amount, principal and interest, respectively.
T = p + i
(v) Let l and b be the length and breadth of the rectangle, respectively.
Perimeter of rectangle = 2(l + b)
(vi) Let a be the side of the square.
Perimeter of the square = 4a