Exterior For example You have a triangle with angles 20 30 and 130 The exterior angle of 130 is 50 as 130+50=180 Angles on a straight line =180 20+30=180-130
The formula for finding the surface area of a cube is A=6y^2 where y is the side length. we know a=96. so we just isolate y. 96/6= 6y^2 / 6 16=y^2 sqrt (16) = sqrt(y^2) 4=y