Triangle abc is an equilateral triangle. segment ad measures 18 inches.

triangle a b c is shown. a perpendicular bisector is drawn from point a to point d on side b c. the length of a d is 18. line a c cuts side b c into 2 equal parts.

Circle a has a diameter of 7 inches, a circumference of 21.98 inches, and an area of 38.465 square inches. the diameter of circle b is 6 inches, the circumference is 18.84 inches, and the area is 28.26 square inches. part a: using the formula for circumference, solve for the value of pi for each circle. (4 points) part b: use the formula for area and solve for the value of pi for each circle. (4 points)