Maths Question

matthew

Well-known member

Sep 20, 2009

2,413

Ovingdean, United Kingdom

• Aug 3, 2015

• #1

Can someone please tell me how to calculate the length of a roof when you have the angle of the the roof and the adjacent length?

Basically have the length using google earths measurement but this does not factor in the slope of the roof.

Thank you!

 

M

MattBackHome

Well-known member

Jul 7, 2003

11,720

• Aug 3, 2015

• #2

SOHCAHTOA innit.

 

E

essbee

New member

Jan 5, 2005

3,656

• Aug 3, 2015

• #3

Get up there and measure it, you lazy bast**d

 

StonehamPark

#Brighton-Nil

Oct 30, 2010

9,773

BC, Canada

• Aug 3, 2015

• #4

BODMAS - Right?

 

Titanic

Super Moderator

Helpful Moderator

Jul 5, 2003

39,057

West Sussex

• Aug 3, 2015

• #5

Can you draw a simple picture, with the known values?

 

StonehamPark

#Brighton-Nil

Oct 30, 2010

9,773

BC, Canada

• Aug 3, 2015

• #6

Titanic said:

Can you draw a simple picture, with the known values?

Click to expand...

 

G

Gwylan

Well-known member

Jul 5, 2003

31,336

Uffern

• Aug 3, 2015

• #7

The cat sat on an orange and howled horribly

 

Herr Tubthumper

Well-known member

NSC Patron

Jul 11, 2003

59,467

The Fatherland

• Aug 3, 2015

• #8

Gwylan said:

The cat sat on an orange and howled horribly

Click to expand...

Silly old harry......

 

Gazwag

5 millionth post poster

Mar 4, 2004

30,130

Bexhill-on-Sea

• Aug 3, 2015

• #9

Gwylan said:

The cat shit on an orangetree and howled horribly

Click to expand...

Not surprised with a hot poker up its arse

 

Colonel Angus

New member

Mar 3, 2012

679

Deep South where it's warm and moist

• Aug 3, 2015

• #10

OK, I'll bite.

A roof is a prism (if you have a normal shape roof, but maybe yours is like an aubergine; you might want to look into this) and there is nothing you can do with the properties of the end face that will tell you the roof length which can be anything).

I recommend that you measure the length of your street, then measure the lengths of all the other houses (and the gaps between the houses) and subtract them all from the street length and you should have your answer.

Good luck!

 

matthew

Well-known member

Sep 20, 2009

2,413

Ovingdean, United Kingdom

• Aug 3, 2015

• Thread starter
• #11

StonehamPark said:

Click to expand...

Best I can do - Not sure if the angle's is the right place..

 

StonehamPark

#Brighton-Nil

Oct 30, 2010

9,773

BC, Canada

• Aug 3, 2015

• #12

matthew said:

View attachment 67464

Best I can do - Not sure if the angle's is the right place..

Click to expand...

That's acute picture.

 

A

Arthritic Toe

Well-known member

Nov 25, 2005

2,392

Swindon

• Aug 3, 2015

• #13

cos(30)=16/x
Therefore x=16/cos(30) = 16/0.866 = 18.475

 

Lord Bracknell

On fire

Jul 5, 2003

39,499

104 Upper Grosvenor Street, Mayfair

• Aug 3, 2015

• #14

Pleeeease ... Not another thread about pi.

 

R

ringmerseagulltoo

Active member

Feb 16, 2012

439

• Aug 3, 2015

• #15

You could go into the loft and measure it then allow a bit for the eaves overhang.

 

matthew

Well-known member

Sep 20, 2009

2,413

Ovingdean, United Kingdom

• Aug 3, 2015

• Thread starter
• #16

Arthritic Toe said:

cos(30)=16/x
Therefore x=16/cos(30) = 16/0.866 = 18.475

Click to expand...

Yes. Thank you!

 

Mackenzie

Old Brightonian

Nov 7, 2003

33,534

East Wales

• Aug 3, 2015

• #17

Count the tiles?

 

smeariestbat

New member

May 5, 2012

1,731

• Aug 3, 2015

• #18

i'm gonna be a builder, when the **** am I gonna need trigonometery.
dopey ******* teacher, you dont know **** all.