Question

what is the area of the shaded region? 10 mi 7 mi 12 mi 6 mi square miles

Explanation:

Step1: Calculate area of outer rectangle

The area formula for a rectangle is $A = l\times w$. For the outer - rectangle with length $l = 12$ mi and width $w = 10$ mi, $A_{outer}=12\times10 = 120$ square miles.

Step2: Calculate area of inner rectangle

For the inner - rectangle with length $l = 7$ mi and width $w = 6$ mi, $A_{inner}=7\times6=42$ square miles.

Step3: Calculate area of shaded region

The area of the shaded region is the difference between the area of the outer rectangle and the area of the inner rectangle. So $A = A_{outer}-A_{inner}=120 - 42=78$ square miles.

Answer:

78