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Help with new spec (9-1) questions

This is a question from a foundation tier paper that I am unable to answer. I would appreciate it if someone could help me out with it.

Thanks in advance
Split the trapezium into compound shapes, construct a triangle at the end and use Pythagoras' theorem to work out the length of the hypotenuse.
Reply 2
Original post by NotNotBatman
Split the trapezium into compound shapes, construct a triangle at the end and use Pythagoras' theorem to work out the length of the hypotenuse.


Oh I haven't even done Pythagoras' theorem at school yet. Could you show me the workings?
Original post by JackT2000
Oh I haven't even done Pythagoras' theorem at school yet. Could you show me the workings?


For any right-angled triangle, the following is true:

Original post by JackT2000
Oh I haven't even done Pythagoras' theorem at school yet. Could you show me the workings?


What year are you in by the way?
Reply 5
Original post by JackT2000
Oh I haven't even done Pythagoras' theorem at school yet. Could you show me the workings?


When you have a right triangle like in the image below, Pythagora's theorem states that a2+b2=c2a^2+b^2=c^2, where c has to be the hypotenuse.
Reply 6
Original post by LifeIsFine
What year are you in by the way?


Year 10 going into year 11 tomorrow
Original post by JackT2000
Year 10 going into year 11 tomorrow


cool, good luck with GCSE's next year!
Reply 8
Original post by RDKGames
For any right-angled triangle, the following is true:



So once I have split the shape into a square and triangle how do I find the value of a and b to get c^2?
Original post by JackT2000
So once I have split the shape into a square and triangle how do I find the value of a and b to get c^2?


You're not splitting the shape into a 'square' and a triangle, a square is a very specific shape and not required in this question.

You're splitting the trapezium into a rectangle and a triangle.

You know the bottom width of the trapezium is 9cm. When you split it into the rectangle and triangle, both of their bottom widths must add up to 9. You also know the rectangle's bottom width because you can use other lengths as wells as facts on lengths of a rectangle to work that one out, hence take that away from 9 to get the bottom width of the triangle.

The height of the triangle is also straight forward because it is the same length as the right side of the rectangle.
(edited 7 years ago)
Reply 10
Original post by RDKGames
You're not splitting the shape into a 'square' and a triangle, a square is a very specific shape and not required in this question.

You're splitting the trapezium into a rectangle and a triangle.

You know the bottom width of the trapezium is 9cm. When you split it into the rectangle and triangle, both of their bottom widths must add up to 9. You also know the rectangle's bottom width because you can use other lengths as wells as facts on lengths of a rectangle to work that one out, hence take that away from 9 to get the bottom width of the triangle.

The height of the triangle is also straight forward because it is the same length as the right side of the rectangle.


Screenshot_1.png
The lengths are in red. So how do I find the missing length?

Do I use a^2 + b^2 = c^2 ?

If I sub the lengths into this like so I get 29cm

5^2 + 2^2 = 29
(edited 7 years ago)
Original post by JackT2000
Screenshot_1.png
The lengths are in red. So how do I find the missing length?

Do I use a^2 + b^2 = c^2 ?

If I sub the lengths into this like so I get 29cm

5^2 + 2^2 = 29


Yeah Pythagoras so this part is just root 29 :smile:
Original post by JackT2000
Screenshot_1.png
The lengths are in red. So how do I find the missing length?

Do I use a^2 + b^2 = c^2 ?

If I sub the lengths into this like so I get 29cm

5^2 + 2^2 = 29


that is correct. *
Original post by JackT2000
Screenshot_1.png
The lengths are in red. So how do I find the missing length?

Do I use a^2 + b^2 = c^2 ?

If I sub the lengths into this like so I get 29cm

5^2 + 2^2 = 29


c2=29 c^2 =29 so c=29 c =\sqrt{29}
Original post by JackT2000

The lengths are in red. So how do I find the missing length?

Do I use a^2 + b^2 = c^2 ?

If I sub the lengths into this like so I get 29cm

5^2 + 2^2 = 29


Correctly done. You get 29 because it is the length of the hypotenuse SQUARED. So since c2=29c^2=29 and c is our wanted length, I'm sure you know what to do here to get it.
Reply 15
Original post by RDKGames
Correctly done. You get 29 because it is the length of the hypotenuse SQUARED. So since c2=29c^2=29 and c is our wanted length, I'm sure you know what to do here to get it.


This attachment is my workings so far, how can I find the area of the square?
Original post by JackT2000
This attachment is my workings so far, how can I find the area of the square?


Your workings are wrong. You used 29 when that's not the correct length, you didn't square root it.

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