The temperature went from -12°F to 18°F. Which of the following expressions could be used to find how much the temperature changed? 1. -12-18 2. 18+(-12) 3. -12-18 4. 18-(-12)

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)