Determine the approximate length of AC (please provide a good explanation, I want to understand this better!)
A: 7 Units
B: 7.07 Units
C: 5 Units
D: 1 Unit

B:   7.07 units

Step-by-step explanation:

We see a radius of circle A labeled 3, so we know that the other radius of circle A that contains the side of the rectangle also measures 3 units. The side of the rectangle measures 2, so the part of the radius of circle A that is not part of the rectangle measures 1 unit. That is one leg of the right triangle.

Opposite sides of a rectangle are congruent, so the side of the rectangle opposite the side that measures 7 also measures 7. That is the other leg of the right triangle. Now we use the Pythagorean theorem to find AC which is the hypotenuse of the right triangle.

a² + b² = c²

1² + 7² = c²

1 + 49 = c²

c² = 50

c = √50

c = 7.07