Answer: C) 611 square miles
Step-by-step explanation:
Create a perpendicular from the vertex (A) to the base (BC) which creates a 30-60-90 triangle on the right side. Label this point D.
Use the 30-60-90 triangle rules (b - b√3 - 2b) to calculate the height of the triangle.
2b = 47 --> b = 23.5
AD = b√3 = 23.5√3
Area of a triangle = (1/2) base x height
= (1/2) 30 x 23.5√3
= 610.5479
≈ 611
