Question 497139
You will need to use the distance formula to find the distances between all three points.
d = {{{sqrt((x2 - x1)^2 + (y2 - y1)^2))}}}
AB = {{{sqrt((4 - - 4)^2 + (5 - - 1)^2))}}}
AB ={{{sqrt((8)^2 + (6)^2))}}}
AB = {{{sqrt(100))}}}
AB = 10
BC = {{{sqrt((4 - 4)^2 + (-2 - 5)^2))}}}
BC = {{{sqrt((0)^2 + (-7)^2))}}}
BC = {{{sqrt(-7)^2))}}}
BC = {{{sqrt(49))}}}
BC = 7
AC = {{{sqrt((4 --4)^2 + (-2 --1)^2))}}}
AC = {{{sqrt((8)^2 + (-1)^2))}}}
AC = {{{sqrt(65))}}}
AC = 8.06
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To find the perimeter, you will add up the three sides
10 + 7 + 8.06 = 25.06.
Cleomenius.