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How do I answer C1 questions where by

they give me three co-ordinates of a triangle and tell me to work out the area but you don't know the height of the triangle since the base doesn't make a straight line
Work out the length of each of the sides using Pythagoras, then use the cosine rule to work out one of the angles
then use the formula area= 1/2 a b sin(c)
Reply 2
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YeSand
5
Original post by DedeM9
they give me three co-ordinates of a triangle and tell me to work out the area but you don't know the height of the triangle since the base doesn't make a straight line


Give me the picture of the question since you're not being specific with the details here... -.-
Reply 3
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YeSand
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Original post by Radical Lemon
Work out the length of each of the sides using Pythagoras, then use the cosine rule to work out one of the angles
then use the formula area= 1/2 a b sin(c)


You don't need to know that for C1??
Reply 4
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3121
21
Original post by Radical Lemon
Work out the length of each of the sides using Pythagoras, then use the cosine rule to work out one of the angles
then use the formula area= 1/2 a b sin(c)


Im pretty sure if it's C1 it'll be the basic 1/2*base*height?
Original post by zayn008
Im pretty sure if it's C1 it'll be the basic 1/2*base*height?

Yup I think in C1 there's always a perpendicular angle.
Reply 6
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3121
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AH! You use the mid point of the base and the top co-ordinate to work out the height!!!!!
Reply 7
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3121
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Original post by XOR_
Yup I think in C1 there's always a perpendicular angle.


Yeah usually they build it up, so I bet before this question they asked to show 2 lines are perpendicular, that or you can use the base mid points and the top co-ordinate to get the length of the height
Original post by zayn008
Im pretty sure if it's C1 it'll be the basic 1/2*base*height?


I believe this is correct.
Remember it is base times PERPENDICULAR (vertical) height, not the slanted height. :smile:
Original post by Zacken
It's usually referred to as the perpendicular height. :smile:
(edited 7 years ago)
Original post by zayn008
AH! You use the mid point of the base and the top co-ordinate to work out the height!!!!!


Do you have an example questions?
Reply 10
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YeSand
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Original post by Someboady
I believe this is correct.
Remember it is base times VERTICAL height, not the slanted height. :smile:


Doing past papers... and those are the only questions I've found.
Reply 11
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Zacken
22
Original post by Someboady
I believe this is correct.
Remember it is base times VERTICAL height, not the slanted height. :smile:


It's usually referred to as the perpendicular height. :smile:
Original post by Zacken
It's usually referred to as the perpendicular height. :smile:


Sorry...still a bit of a maths noob :frown: I'll quote you in.
Reply 13
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Zacken
22
Original post by Someboady
Sorry...still a bit of a maths noob :frown: I'll quote you in.


You weren't wrong at all, nothing nooby about it. Was just a quick tip. :smile:

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