Question

Given an equilateral triangle with two vertices located at (-8, -5) and (3, 7), what is its perimeter?

Answer 1

An equilateral triangle has 3 sides of equal length
find the length of 1 side and that is the length of te other 2 sides
so find the length and times 3

we need to find the distance betwen the points (-8,-5) and (3,7)

distance between the points (x1,y1) and (x2,y2) is
$D=\sqrt{(x_1-x_2)^2+(y_1-y_2)^2}$
so
distance between (-8,-5) and (3,7) is
$D=\sqrt{(-8-3)^2+(-5-7)^2}$
$D=\sqrt{(-11)^2+(-12)^2}$
$D=\sqrt{121+144}$
$D=\sqrt{265}$

the distance is √265
the perimiter is 3√265 units