Use basic trigonometric identities to simplify the expression: sin (x) cos (x) sec (x) = ? a. sin(x) b. tan(x) sec(x) c. sec(x) d. cos(x)

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)