The arc length of QR is 120/360 of 16pi, which is the circumference. That is 16pi/3
The central angle in radians is 2/3pi. 180 degrees in radiansis pi and 360 is 2pi.
The area of the sector is 64pi/3. Like 71, we just set up a proportion again. it is just a third of the total area
The equation is (x-3)^2+(y+4)^2=4
Because the basic form is (x-h)^2+(y-k)^2=r^2 and (h,k) is the center and r is the radius.
We can do the last one by completing the square.
We take the square of half of the coefficients.
Sorry if these were not detailed, I didn't have a calculator and was in a hurry.