Solution:Indifference curve for two normal goods is a downward sloping but not straight line its curve of convex shape.
(1). I.C. being downward sloping means that when consumption of one good increases then consumption of other goods decreases slopes downward or it shows negative slope.

(2). The degree of convexity of an indifference curve depend upon the rate of fall in the marginal rate of X for Y.
The two goods are perfect substitutes of each other the IC is a straight line.
Greater the MRS greater will be the convexity of the IC. In the perfect substitute goods MRSxy is equal to one.
(3). The two goods are perfect complementary then IC become straight line which is Right angle bent which is convex to the origin. In perfect complimentary goods MRSxy is equal to zero incase of Bad' commodity IC shift backward.