Question 1172843
P=2L+2w; worth drawing this.
(1/2)P=L+W (not commonly used but simpler in some ways.)
64=L+W, but L=2W+1
so 64=2W+1+W
3W=63
W=21 cm
L=43cm
perimeter is 2(21)+2(43) or 128 cm.