Triangle's Area within a Trapezoid

Question

I am having trouble with the above question, I know the answer is triangle RTS but I cant seem to find the reasons.

I know that VT is parallel to RS but that doesnt mean RV is equal to TS. Besides, the question said this is not an isosceles trapezoid so it is not equal.

I was thinking to proceed by finding a way to prove the triangles RTS and RVS are equal. So I could only find a common side which is RS. I believe the information about the diagonals play a role into this but I'm not sure how to proceed.

Answer 1

It's $\Delta RTS$ as, both triangle have base $\overline {RS}$ and as $\overline{RS}\mid\mid VT$ hence, their height is same. So, their area is same.

Answer 2

$\triangle RTS$ and $\triangle RSV$ have the same base, namely $|\overline{RS}|$, and the same height relative to this base, which is the distance between $RS$ and $TV$, then $$\text{Area }(RTS)=\text{Area }(RSV)$$