Question 601237
Find the distance between DE, EF, Df . Then decide the type of triangle

Use distance formula
L(DE)
Distance between two points													
x1	y1	x2	y2										
													
6	-6	39	-12										
d=	{{{sqrt((y2-y1)^2+(x2-x1)^2)}}}												
d={{{sqrt((-12-(-6))^2+(39	-6)^2	)}}}
d=	{{{sqrt((-6)^2+(33)^2	)}}}				
d=	{{{sqrt((1125))}}}								
l(DE)=	33.54	

l(EF)

x1	y1	x2	y2										
													
39	-12	24	18										
d={{{sqrt((y2-y1)^2+(x2-x1)^2)}}}												
d={{{sqrt((18-(-12))^2+(24	-39)^2	)}}}
d=	{{{sqrt((30)^2+(-15)^2	)}}}				
d=	{{{sqrt((1125)  	)}}}								
d=	33.54	

l(EF)
x1	y1	x2	y2										
													
24	18	6	-6										
d=	{{{sqrt((y2-y1)^2+(x2-x1)^2)}}}												
d={{{sqrt((-6(-18))^2+(6	-24)^2)}}}
d=	{{{sqrt((-24)^2+(	-18)^2	)}}}				
d=	{{{sqrt((900))}}}								
d=	30.00	

Two sides are equal hence aisoscles triangle											
m.ananth@hotmail.ca