Respuesta :
Hi there,
A rectangle has got 2 lengths, and 2 widths, so we have got the formula:
P = 2·L + 2·l, where P - perimeter, L - length, and l - width.
P -- 2·L = 2·l, if we divide everything by 2, we have
P/2 -- L = l, so l = P/2 -- L = 76/2 -- 20 = 38 -- 20 = 18 cm, so l = 18 cm.
Was it difficult ?
Green eyes.
The fromula of a perimeter of rectangle:
P = 2(l + w)
We have P = 76 cm and l = 20 cm.
Substitute:
2(20 + w) = 76 use distrubutive property
(2)(20) + (2)(w) = 76
40 + 2w = 76 subtract 40 from both sides
2w = 36 divide both sides by 2
w = 18