Can y’all help me on question 20?!

Aline passes through the point (2, -4) and has a slope of 0, what is the equation of the line? plz fast

An arc subtends a central angle measuring 7pi/4 radians what fraction of the circumference is this arc?

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)