I have attached the image of triangles QRS.
First lets determine the inner angles of the triangle. Angle Q = 180 - 132 = 48
Angle S = 180 - 124 = 56. Therefore, angle S = 180 - 48 - 56 = 76.
To find the area of a triangle we need the formula: A = hb/2 where a straight line is draw from angle S to side QS to form a right triangle. The line from angle S to the base QS, is called h. We just solve for side h which we can do using:
sin76 = h/21
h = 20.38
b = 23.43
A = (23.43)(20.38)/2
A = 238.7 square units.
The answer is option C) 238.7 square units.
