to find the percentage, we take the tax over the subtotal
percentage = tax/subtotal
multiply by 100% to change from decimal to percent form
they are the same length
to solve this, let's draw lines ae and de. since ab = cd, gd = fa. using the pythagorean theorem, we have that ef^2 = ae^2-fa^2 and eg^2 = de^2-dg^2. because ae and de are radii of the same circle, they are equal, and since dg = fa, we can find that eg^2 = ae^2-fa^2 too, so this means that they are the same length.
i originally put fa switched, so it was an acronym for a bad word. good thing i found out!
slope intercept form is y=mx+b where m is the slope and b is the y-intercept. the line crosses through (0,3) so b=3.
to find the slope, count the units between two points and form a ratio of vertical to horizontal distance. count from (0,3) to (1,0). it drops -3 units and moves to the right 1 unit. so m = -3/1 = -3.
the equation is y = -3x+3