Geometry

Total angle measure of n sided polygon

Area of equilateral triangle

Ratio of the sides for a 30-60-90 triangle is

Perpendicular lines have negative slopes

y= mx +b
x intercept = -b/m
y intercept = b
slope m= (y2-y1)/(x2-x1)
b can be found by substituting the points in the eq y=mx+b.

If (x1,y1) and (x2,y2) are two points on a line, then the slope of the line is

Ratio of the side1:side2:hyp for a 45-45-90 triangle is