...you forgot the extra pipe to replace the one that that gets robbed or cut too short or squashed under a pack of blocks...
Incidentally, I never figured out how the OP came to use Pythagoras given that there was only one dimension given, along with a nangle (1:12) and a totally irrelevant IL. I know you could use the fall to calculate the depth, but surely trig is quicker?
Hi, thanks for taking the time to answer my Question. I used Pythagoras as did every one in my group. I didn't know until recently that trig would be better. I also have to say that it was my lazy and useless surveying tutor (head of department as well) who set the question then marked our answers and passed them! (actually he's the worst Tutor I have ever had!!!) I'm now having to do the whole module again because of his shame full teaching practices. You need to deliver the right material in the right way to be effective. By the by am a merit student and a mature one at that.
Tony I went thro your trig calc, I couldn't see where you got 0.9966 from. Can you clarify that for me thanks.
A thing I found out today was that-
If you are unsure if you should use Pythagoras or trigonometry? Remember that Pythagoras uses only sides, trigonometry needs an angle and sides.-I'll be remembering that one.
i use Pythagoras's theorem on a daily basis ,when you have a known straight line (a datum) then you can get a 90 deg. angle by using 3 4 5 and multiples thereof, trig is ok for roofs as i recall from my misspent yoof it is "silly old harry,chased a horse,through our alley" which converts to sin=opposite over hypotenuse,cosine is adjacent over hypotenuse,and tangent is opposite over adjacent
the only problem is you need a scientific calculator or a logarithim book to do it
cheers LLL :;):
Nick - the value 0.9966 is the cosine of 4.76°. It can be found on the better calculators or, if your granparents are around, ask them if they havce a book of log tables!
You're right about Pythagoras using sides (note the plural) while trig requires at least one side and one angle. The problem posed in your OP gives one "side", the 12.3m length, and one angle, the 1:12 gradient, which is why I opted for trig.
when i did electronics the resistor colour code was very racist but instantly memorable and it was the one our teacher told us
black b******ds ride only young girls but virgins go without
black,brown ,red,orange,yellow,green,blue,violet,grey,white
its strange how silly thing stick in your mind like that , 25 years since i heard it,i know we had 1 teacher and he used to call a coloured lad "spear chucker" he would be sacked on the spot now,and rightly so
cheers LLL
I'm now having to do the whole module again because of his shame full teaching practices. You need to deliver the right material in the right way to be effective. By the by am a merit student and a mature one at that.
