Explain

Height = Sin(20) x 9 = 3.078

Area = Base x Height x 1/2

Area = 14 x 3.078 x 1/2

Area =21.5 cm^2

Answer of the above question is 21.5 cm^2. You just implement the forumla and get the answer.

You are better to use the area formula.

area = 1/2 *absinC

= 1/2 * (9*14*sin 20)

etc