Question 160621
Vertex {{{A}}} in on the origin, so Vertex {{{A}}} coordinates are ({{{0}}},{{{0}}}).

Vertex {{{B}}} lies on the {{{y-axis}}}, so coordinates are ({{{0}}},{{{t}}})

Vertex {{{C}}} coordinates are ({{{t}}},{{{t}}})

Vertex {{{D}}}lies on the {{{x-axis}}}, so  coordinates are ({{{t}}},{{{0}}})


{{{drawing( 160, 160, -10, 10, -10, 10,line( -6, -6,4,-6) , line( -6, -6,-6,4), line( -6, 4,4,4) , line( 4, 4,4,-6) ,locate( -6.5,-6.5,A(0,0)),locate( 4.5,-6.5,D(t,0)),locate( 4.5,4.5,C(t,t)),locate(-7.5,5,B(0,t)))}}}