Is AB the Median of QRST?
AB is the median of trapezoid QRST.
The length of the median of a trapezoid is one-half the sum of the lengths of the two bases.
Substitute known values for RS and QT and solve for AB.
Since JK is a median of trapezoid ABTQ,
All variables except JK should be known at this point, so substitute values for AB and QT and find JK.