Use the law of cosines to solve the triangle if possible a

Use the law of cosines to solve the triangle, if possible. a = 18 m, b = 21 m, c = 32 m Find the measure of angle A. Select the correct choice below and, if necessary, fill in the answer box to complete your choice. A = degree There is no solution.

Solution

a=18,b=21,c=32

Using cosine law we get

cos A= (b^2 + c^2 -a^2)/2bc=(21^2 +32^2-18^2)/2(21)(32)

cos A= 1141/1344

A=31.90 degree

cos B=(a^2 +c^2-b^2)/(2ac)= (18^2 + 32^2 - 21^2)/(2*18*32)

cos B= 907/1152

B=38.06 degree

C=180-(A+B)=180-(31.90+38.06)= 110.04 degree