the first rectangle has a perimeter of 380 and the length of the rectangle is w+20 the width is unknown
the second rectangle has a perimeter of 640 and the length of the rectangle is 3w - 12 the width is unknown
the third rectangle has a perimeter of 220 and the length of the rectangle is 2w - 40 the width is unknown
the fourth rectangle has a perimeter of 380 and the 5w + 10 the width is unknown
the last rectangle has a perimeter of 300 and the length of the rectangle is w + 90 the width is unknown
2006-09-09 04:39:23 · 6 answers · asked by ketchup02145 2 in Science & Mathematics ➔ Mathematics
l = w + 20
perimeter = 2w + 2l
380 = 2w + 2(w+20)
380 = 2w + 2w + 40
340 = 4w
width = 85
2l + 2w = 380
2l + 170 = 380
2l = 210
length = 105
Do the other questions the same way.
2006-09-09 05:29:48 · answer #1 · answered by Anonymous · 1⤊ 0⤋
perimeter of a rectangle=2*length+2*width
P=2*L+2*W
1ST RECTANGLE,
380=2*(W+20)+2W
380=2W+40+2W
380-40=4W
340/4=85=W
2ND RECTANGLE,
640=2*(3W-12)+2W
640=6W-24+2W
640-24=8W
616/8=77=W
3RD RECTANGLE,
220=2*(2W-40)+2W
220=4W-80+2W
220-40=6W
180/6=30=W
4TH RECTANGLE,
380=2*(5W+10)+2W
380=10W+20+2W
380-20=12W
360/12=50=W
5TH RECTANGLE,
300=2*(W+90)+2W
300=2W+180+2W
300-180=4W
120/4=30=W
LENGTH=P-2W/2=380-2*85/2=105(1ST)
=640-2*77/2=243(2ND)
=220-2*30/2=80(3RD)
=380-2*50/2=280/2=140(4TH)
=300-2*30/2=240/2=120(5TH)
2006-09-09 13:10:45 · answer #2 · answered by Anonymous · 0⤊ 1⤋
I will only do the first one:
perimeter = 2 x with + 2 x length
380 = 2w + 2(w+20)
380 = 2w + 2w + 40
340 = 4w
w = 85 and length = 105
You should be able to solve the other problems yourself
2006-09-09 11:54:38 · answer #3 · answered by mitch_online_nl 3 · 2⤊ 0⤋
The rectangle has four sides...two are called the width and two are called the length. The sum of all four sides equals 380.
So (w+40)+(W+40)+W+W = 380
Solving for W you get
4W+80=380
4W=380-80=300
W=380divided by 4
2006-09-09 11:59:40 · answer #4 · answered by richard Alvarado 4 · 1⤊ 0⤋
1. length = w+20 therefore perimeter = 4w +40 i.e. w+20 twice +w+w. therfore w = 340/4 = 85, l= 105.
2. w+w+6w-24 =640 8w = (640+24)/8, w = 83 length = 237.
Can you do the other two yourself now or would you like more help?
2006-09-09 11:57:34 · answer #5 · answered by Anonymous · 0⤊ 1⤋
The first rectangle is
380=w+w+w+20+w+20
380=4w+40
340=4w
85=w
105=L
im working on the others atm
the fourth one is
380=w+w+5w+10+5w+10
380=12w+20
360=12w
30=w
160=L
im still working
the last one is
300=w+w+w+90+w+90
300=4w+180
120=4w
30=w
120=L
hold on for a bit longer
i dont think the other 2 work properly cas i cant find an answer for them sorry :(
2006-09-09 12:09:08 · answer #6 · answered by Ruth W 2 · 0⤊ 1⤋