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# Need help with GCSE Maths question watch

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1. An answer or guidance would be greatly appreciated.
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2. (Original post by gs--xa)
An answer or guidance would be greatly appreciated.
so you know the perimeter so therefore you should be able to find the length of each of the edges, tis will in th=urn help you to find the perimeter of the rectangle. good luck
3. perimeter of rectangle = 20
lets take x and y as sides of the rectangle
perimeter = 2(x+y)
20 = 2(x+y)
10 = x+y
X= 10-y (1)
area of rectangle = area of equilateral triangle ( in this question)
area of rectangle = xy
area of equilateral triangle = root3/4 * asquared ( in this case a is 2x)
area of eq... triangle = root3/4 * 4xsquared

xy = root3/4 * 4xsquared
dividing both sides by x
y= root3/4 * 4x
we know x= 10-y
y= root3/4 * 40-4y
5y= 10root3
y= 2root3
x= 10-2root3
perimeter of equi... triangle = 3a ( a = 2x)
perimeter = 6x
= 6( 10 - 2root3)
= 39.2 cm ( 1dp)
the method is correct but might have done some calculation error. ( is this the right answer??)
4. (Original post by Brudor2000)
perimeter of rectangle = 20
lets take x and y as sides of the rectangle
perimeter = 2(x+y)
20 = 2(x+y)
10 = x+y
X= 10-y (1)
area of rectangle = area of equilateral triangle ( in this question)
area of rectangle = xy
area of equilateral triangle = root3/4 * asquared ( in this case a is 2x)
area of eq... triangle = root3/4 * 4xsquared

xy = root3/4 * 4xsquared
dividing both sides by x
y= root3/4 * 4x
we know x= 10-y
y= root3/4 * 40-4y
5y= 10root3
y= 2root3
x= 10-2root3
perimeter of equi... triangle = 3a ( a = 2x)
perimeter = 6x
= 6( 10 - 2root3)
= 39.2 cm ( 1dp)
the method is correct but might have done some calculation error. ( is this the right answer??)
Thanks for the help but I thought you couldn't add 4y to both sides if you are multiplying root3/4 by (40-4y)?
5. (Original post by gs--xa)
Thanks for the help but I thought you couldn't add 4y to both sides if you are multiplying root3/4 by (40-4y)?
your right!! you add root3y to both sides (root3/4*4y= root3y)
6. (Original post by Brudor2000)
perimeter of rectangle = 20
lets take x and y as sides of the rectangle
perimeter = 2(x+y)
20 = 2(x+y)
10 = x+y
X= 10-y (1)
area of rectangle = area of equilateral triangle ( in this question)
area of rectangle = xy
area of equilateral triangle = root3/4 * asquared ( in this case a is 2x)
area of eq... triangle = root3/4 * 4xsquared

xy = root3/4 * 4xsquared
dividing both sides by x
y= root3/4 * 4x
we know x= 10-y
y= root3/4 * 40-4y
5y= 10root3
y= 2root3
x= 10-2root3
perimeter of equi... triangle = 3a ( a = 2x)
perimeter = 6x
= 6( 10 - 2root3)
= 39.2 cm ( 1dp)
the method is correct but might have done some calculation error. ( is this the right answer??)
Please do not post full maths solutions you are only supposed to give hints as the rules state in the maths forum
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7. (Original post by Y11_Maths)
Please do not post full maths solutions you are only supposed to give hints as the rules state in the maths forum
oh! M extremely sorry! Didn't know that. will make sure to post only hints next time.
8. Is this calculator or non calculator?
Posted on the TSR App. Download from Apple or Google Play
9. Here's a tip:

The height of an equilateral triangle is times the length of the triangle.

length of the rectangle is times the width.
10. (Original post by Y11_Maths)
Is this calculator or non calculator?
It was from a calculator paper.
11. (Original post by Brudor2000)
your right!! you add root3y to both sides (root3/4*4y= root3y)
(Original post by AddQ7)
Here's a tip:

The height of an equilateral triangle is times the length of the triangle.

length of the rectangle is times the width.
Thanks for the help

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