<PRE><B>Question 85376</B>
I am really confused with this question, please help
Use a coordinate geometry to prove that the quadrilateral OPQR with vertices O(0,0), P(9,3),Q(9,8), and R(-3,4) is an isosceles trapezoid
SLOPE OF OP=(3-0)/(9-0)=3/9=1/3
SLOPE OF QR=(4-8)/(-3-9)=-4/-12=1/3
HENCE OP||QR
HENCE OPQR IS A TAPEZIUM 
OR^2=(-3-0)^2+(4-0)^2=9+16=25
PQ^2=(9-9)^2+(3-8)^2=0+25=25
HENCE 
OR=PQ 
HENCE IT IS AN ISOSCELES TRAPEZIUM </PRE>