1) Using the distance formula, we get the length of QR is 13, and so is the length of RS. Therefore, this statement is true.
2) Using the distance formula, we get that TS=13 and QT=3. This means the perimeter is 13+13+13+3=42, so this is also true.
3) ST is 13 but QT is 3, so ST is 13-3=10 units longer than ST, not 9. Therefore, this is false.
4) This is true (just substituting into the distance formula)