Its point P because the lines between 1 and 2 are 1/4 2/4 and 3/4 and its looking for 1 1/4 so the correct is the line after number 1 on the x axis and the y axis is 2 which you can see p is located it
P = 2(l + w)
p = 356
l = 96
356 = 2(96 + w)
356 = 192 + 2w
356 - 192 = 2w
164 = 2w
164/2 = w
82 = w
check....
p = 2(l + w)
356 = 2(96 + 82)
356 = 2(178)
356 = 356 (correct)
so the width (w) = 82 cm