The perimeter of a rectangle is three times its length. Its area is 800 square units. What are its dimensions?

Answer 1

four sides: a,b,c,d and a=c, b=d

Sides:
a+c+b+d = 3*a
a+a+b+b = 3*a (because a=c and b=d)
2a +2b = 3a (simplify)
2b =a (removed 2a from both sides)
b = 1/2 a (One side is half the other)

Surface:

a * b = 800

2b * b = 800 (a is twice b)
2 * (b*b) = 800 ( [p * q] * r equals p * [q * r])
b*b = 400 (both ends divided by 2)
b = 20 (square root of 400, positive answer only)

You know b = 1/2 a, and b=20 ---> a=40

Dimensions: 20 by 40

Answer 2

The two equations you are working with are:

2L + 2W = 3L (Perimeter is 3 times the Length)

and

LW = 800 (The Area is 800)

Then you just solve,

2W = L and substitute this into the second equation:

(2W)(W) = 800
2W^2 = 800
W^2 = 400
W = 20

Then substitute the value of W (20) into either equation to get a value of 40 for L.

W = 20
L = 40

Answer 3

area of sq. is one hundred forty four. sq. root of one hundred forty four is 12 so sq. has factors 12 cm. 4 x 12 = 40 8 so perimeter is 40 8 cm. Rectangle has same perimeter, to that end length is two times width so 2x + x + 2x + x = 48cm. Re-manage to 6x = 40 8. Divide 40 8 with the aid of 6 to get x = 8cm. So area of rectangle is two(8) x 8 = sixteen x 8 = 128 cmsq. 2 squares next to one yet another, factor length 8cm, area 64cmsq so area of rectangle is 128cmsq.

Answer 4

p = 2l + 2w
3l = 2l + 2w
l = 2w

l x w = 800
2w x w = 800
w^2 = 800/2=400
w = sqrt (400) = 20
l = 2w = 40

Dimensions: 40 x 20

Answer 5

Let

L = length
W = width
P = perimeter
A = area

Given

P = 2L + 2W = 3L
A = 800

Find L and W.

We have

P = 2L + 2W = 3L
2W = L

A = LW = (2W)W = 2W² = 800
W² = 400
W = 20
L = 2W = 2*20 = 40

The rectangle is 20 by 40.

Answer 6

bh=800 h=800/b
3b= 2h+2b

3b=2(800/b)+2b
3b= 1600/b+2b
b2= 1600
b=40

(40)h=800
h= 20

The measurements of the sides are 40 and 20

Answer 7

P = 3L = 2(W+L)
L = 2W

LW = 800
2W^2 = 800
W = 20
L = 40