To find the perimeter of the triangle you need to find the distance between the three pairs of point.
(-2, 2) and (6, 8)
(-2, 2) and (6, 2)
(6, 2) and (6, 8)
The formula for calculating the distance between two points is:
#d = sqrt((color(red)(x_2) - color(blue)(x_1))^2 + (color(red)(y_2) - color(blue)(y_1))^2)#
Calculating these three distances and then adding gives:
#p = sqrt((color(red)(6) - color(blue)(-2))^2 + (color(red)(8) - color(blue)(2))^2) + sqrt((color(red)(6) - color(blue)(-2))^2 + (color(red)(2) - color(blue)(2))^2) + sqrt((color(red)(6) - color(blue)(6))^2 + (color(red)(8) - color(blue)(2))^2)#
#p = sqrt((color(red)(6) + color(blue)(2))^2 + (color(red)(8) - color(blue)(2))^2) + sqrt((color(red)(6) + color(blue)(2))^2 + (color(red)(2) - color(blue)(2))^2) + sqrt((color(red)(6) - color(blue)(6))^2 + (color(red)(8) - color(blue)(2))^2)#
#p = sqrt(8^2 + 6^2) + sqrt(8^2 + 0^2) + sqrt(0^2 + 6^2)#
#p = sqrt(64 + 36) + sqrt(64 + 0) + sqrt(0 + 36)#
#p = sqrt(100) + sqrt(64) + sqrt(36)#
#p = 10 + 8 + 6#
#p = 24#
