if someones room has a perimeter of 200 cm and the width is 25 cm what is the length of the room

Question

i need help with this

Answer 1

P=2l+2w

200=2l+2*25

200=2l+50

200-50=2l

150=2l

l=150/2

l=75 cm

the perimeter of a rectangle is 2 widths plus 2 lengths

half he perimeter is 1 width plus 1 length

half the perimeter is 100 cm and the width is 25 cm, so the length must be 100-25=75 cm