Question

Determine the sign of cos pi divided by seven without using a calculator.

Answer 1

Check the picture below.

now, when you get a fraction of π for the angle, is just really like grabbing π and dividing it in that many pieces, and the angle, is a fraction of π and therefore on those pieces.

π/7 is clearly less than 7π/7 which is π, notice the 7-pieces split in the picture.