D equals 6.6ft, what's the area of the circle

Find the sum of the given arithmetic series. 24 + 17 + 10 + 3 + + (–39)

What is the value of x in the equation 3x4y65, when y=4?

In the given diagram, ∠4 = 45°, ∠5 = 135°, and ∠10 = ∠11. part a: solve for the values of the remaining angles. show all your work for full credit. part b: use complete sentences to describe the angle relationship between the following angle pairs: 1. ∠4 and ∠1 2. ∠7 and ∠5 3. ∠9 and ∠10