Question is:
Two rectangles that are the same except in size.
Rectangle 1(larger of the two):
a)has an area: 64cm^2
b)a long side of 8.2cm
Rectangle 2(smaller of the two)
a)has an area of 25cm^2
b) the long side is unknown, how do we find this out.
I thought you needed to do.
Large area - small area
64 - 25 = 39
The square root of this to change the scale factor to length not area which = 6.2
then do 25(area of smaller) divided by 6.2 = 4? is this correct>
thanks for any help
2007-09-16 07:59:16 · 7 answers · asked by AndyCFCO 1 in Science & Mathematics ➔ Mathematics
Rectangle 1
Area 1 = 64 cm²
l = 8.2 cm
b = 7.8 cm
Rectangle 2
Area 2 = 25 cm²
l = l cm
b = b cm
ratio of areas = A2 / A1 = 25 / 64 = 5 / 8
ratio of sides = √(5/8) = 0.79
Sides in smaller rectangle are:-
0.79 x 8.2 cm = 5.125 cm
0.79 x 7.8 cm = 4.875 cm
2007-09-16 22:00:38 · answer #1 · answered by Como 7 · 2⤊ 0⤋
Pete is right.
You were right in thinking that scale factor is squared when you are dealing with the areas, but your mistake was subtracting the areas.
If you call the scale factor k, then then k squared times 24 (the smaller area) will equal 64 (the larger area).
k^2 x 25 = 64.
From this you can find that k is 8/5.
So 8/5 x the small long side = 8.2 (the big long side),
so the small long side = 5.125.
2007-09-16 09:53:51 · answer #2 · answered by Peggy 2 · 1⤊ 0⤋
Short side of rectangle 1 = 64/8.2 = 7.805 cm
Ratio of sides = 8.2/7.805 = 1.051
Rectangle 2 has same ratio, so
1.051x * x = 25, where x is the shorter of the two sides of rectangle 2.
This can be written 1.051x^2 = 25 or,
x^2 = 25/1.051 = 23.795
So, x = 4.878 cm - this is the shorter side
The longer side is 1.050*4.878 = 5.125 cm
Sorry, Kamcrash, you're wrong!
2007-09-16 09:37:33 · answer #3 · answered by Pete WG 4 · 2⤊ 0⤋
OK ratio of areas=25/64 so ratio of sides =sqrt(25/64)=5/8. Therefore longer side of smaller rect= 8.2x5/8=5.125cm
2007-09-16 10:02:23 · answer #4 · answered by alienfiend1 3 · 1⤊ 1⤋
it extremely is a query of share. paintings out the share by using which the part of the smaller one is smaller than the better one and then decrease the dimensions and breadth by using that share. for example, if the part of the smaller one is 20% under the better one, decrease the long and short aspects of the better one by using 20% to get the long and in need of the smaller one.
2016-10-09 07:23:51 · answer #5 · answered by ? 4 · 0⤊ 0⤋
i don't feel like answering this and doing math on the weekend
2007-09-16 08:06:16 · answer #6 · answered by Anonymous · 0⤊ 1⤋
Yikes!
Pete's right - my bad! Sorry 'bout that.
2007-09-16 08:11:12 · answer #7 · answered by kamcrash 6 · 0⤊ 0⤋