Exercise 3 Page 274

Equilateral triangles have congruent sides. Let's indicate this on the diagram.

Congruent sides have equal length. We can use any two of the given expressions to set up and solve an equation for $x.$ Let's use $WX=6x-12$ and $XY=2x+10.$ We can now substitute $x=\frac{11}{2}$ in the given expressions to get the side lengths of the triangle.

Side	Expression	Substitution	Side Length
$\overline{WX}$	$6x-12$	$6\left(\frac{11}{2}\right)-12$	$WX=21$
$\overline{XY}$	$2x+10$	$2\left(\frac{11}{2}\right)+10$	$XY=21$
$\overline{WY}$	$4x-1$	$4\left(\frac{11}{2}\right)-1$	$WY=21$