x^2 + y^2 \leq 4 $ and y $<x
u done the circle part
y<x, y = x is a line satisfying (0,0) (1,1) (2,2) (3,3), etc
y<x so shade the bottom (using the vertical line test - draw vertical line on the curve, since less than, we choose the bottom)
NB: its less than but NOT EQUAL TO, hence the...