John is making a scale drawing of her triangular vegetable garden. Two sides of the actual garden are 7m and 9m. The angle between these sides is 75o. The drawing is a triangle with side lengths of 14cm and 18cm with an angle of 75o between them. When John drew in the third side of the triangle she found that it was 21cm long. What is the length of the third side of the actual vegetable garden?
