Contribution to resistance of various end contact pads and a square corner.
1) The upper left end contact pad configuration shows a resistor line of width W terminated in a 3W x 3W resistor end pad. The W x W contact via is centered in the end pad. The contribution of 0.65 square is for everything left of the joint between the 3W and W sections of resistor.
2) The upper right end contact pad configuration shows a resistor line of width W terminated with a (W/2) x (W/2) contact via dropped onto the line. The contact via is (W/4) away from the edges of the resistor on three sides. The contribution of 0.14 square is for everything left of the right edge of the contact via.
3) The lower left end contact pad configuration shows a resistor line of width W terminated with a 2W x 2W resistor end pad. The W x W contact via is centered in the end pad. The contribution of 0.35 square is for everything left of the joint between the 2W and W sections of resistor.
4) The lower right figure shows a square corner, which contributes 0.56 square.