Answer:
411.29 mi²
Step-by-step explanation:
The area of the full circle is πr², which here is π(12 mi)², or 144π mi².
Three fourths of this total area comes to 108π mi². To this we add the area of the triangle, which is A = (1/2)(base)(height), or, here, A = (1/2)(12 mi)(12 mi) = 72 mi²
The total is 108π mi² + 72 mi² = 411.29 mi²
