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Need help to calculate question 25 and 26.

Posted: Sun Aug 16, 2009 1:23 am
by scooby1
http://www.topnotchelinks.com/Keystage2 ... r%202.html


I could anbody help me work out the answer on the above link. It is maths paper 2. I have tried to use pythageus to calculate the missing length but getting confused. :?:

Thanks in advance.

Re: Need help to calculate question 25 and 26.

Posted: Sun Aug 16, 2009 7:46 am
by bugsbunny
if you're referring to ques 19-24.

perimeter = sum of all sides of the rectangle.
= 2*Length+ 2*sides
48 = 2*L + 2*W

But it says the length is 2x the width, so L = 2W

48 = 2*(2W) + 2W
Width = 6 and
Length = 2xwidth = 2*6 = 12
total Area = Length*width = 12*6 = 72

Area triangle by logic, the traingle cuts the rectangle into 2 equal parts so the answer is 36.

ques 25 . the figure can be split into two. a rectangle and a triangle, the rectangle has sides of 5cm by 10cm. Area = 50 sq cm.

The triangle has 5cm by 6cm dimensions, so the area is 15sq cm

total area of shape B is 65sq cm.

using Phytagorean theorem, the length of the missing side is 7.8cm

so perimeter is sum of all sides = 5+10+7.8+16

hope this helps :D
scooby1 wrote:http://www.topnotchelinks.com/Keystage2 ... r%202.html


I could anbody help me work out the answer on the above link. It is maths paper 2. I have tried to use pythageus to calculate the missing length but getting confused. :?:

Thanks in advance.

Posted: Sun Aug 16, 2009 3:07 pm
by scooby1
Thanks bugsbunny. I can see how you have worked it out.