Two corners of an isosceles triangle are at (2 ,1 )(2,1) and (8 ,5 )(8,5). If the triangle's area is 4 4, what are the lengths of the triangle's sides?

1 Answer
Feb 2, 2018

Measure of the triangle's sides color(violet)(7.2111, 3.7724, 3.7724)7.2111,3.7724,3.7724

Explanation:

enter image source here

Length of the base (b) is the distance between the given two points (2,1) , (8,5).

Using distance formula,

BC = a = sqrt((x2-x1)^2 + (y2-y1)^2)BC=a=(x2x1)2+(y2y1)2

a = sqrt((8-2)^2 + (5-1)^2) = color(green)(7.2111)a=(82)2+(51)2=7.2111

Area of triangle A = (1/2) a hA=(12)ah

4 = (1/2) 7.2111 * h4=(12)7.2111h

AN = h = (2 * 4) / 7.2111 = color(purple)(1.1094)AN=h=247.2111=1.1094

AB = AC = b = c = sqrt((AN)^2 + (BN)^2)AB=AC=b=c=(AN)2+(BN)2

b = c = sqrt(h^2 + (a/2)^2) = sqrt(1.1094^2 + (7.2111/2)^2) = color(red)(3.7724)b=c=h2+(a2)2=1.10942+(7.21112)2=3.7724

Measure of the triangle's sides color(violet)(7.2111, 3.7724, 3.7724)7.2111,3.7724,3.7724