Using the points where the blue line crosses the X and Y axis:
(0,5) ans (-1, 0)
The slope is the change in Y over the change in X:
0-5 / -1 - 0 = -5/-1 = 5
Slope = 5
Y intercept = y1 = 5
Equation = y = 5x+5
I assume that by square corners you mean 90 degree angles. if this is the case then there are 2 in a pentagon. Hope I helped :)
I think it would have crystal formations if I remember correctly.
Using: A^2+b^2=c^2
A&b= (√10)^2=10
10+10=c^2
20=c^2
(take the square root of 20)
c=2√5
Your answer is D