Question 309806
Start with:
{{{d = sqrt((x[2]-x[1])^2+(y[2]-y[1])^2)}}} where: d = distance, and the x- and y-coordinates of the two given points 1 and 2 are the ({{{x[1]}}},{{{y[1]}}}) and ({{{x[2]}}},{{{y[2]}}}) respectively.
Make the appropriate substitutions.
{{{d = sqrt((12-8)^2+(11-8)^2)}}}
{{{d = sqrt(4^2+3^2)}}}
{{{d = sqrt(16+9)}}}
{{{d = sqrt(25)}}}
{{{highlight(d = 5)}}}