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Pyramid Question (Need some help please)

Hello guys , so i have been doing this homework and i got this question which i have no clue on how to do :/

Please help if u can - with explanation and working out might help me understand the question and the answer a bit more ^^




Thanks
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You can find the length of BD using Pythagoras' Theorem, and then the length of OH using SOHCAHTOA.
Reply 2
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keerthan
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i got the Length of OH As 9.02 i dont know if its right but im really stuck on Part b .
Original post by keerthan
i got the Length of OH As 9.02 i dont know if its right but im really stuck on Part b .


It is incorrect

How did you find that?
Reply 4
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keerthan
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ow it is :/ i got the answer from my friend :frown: so i can workout b .
Original post by keerthan
ow it is :/ i got the answer from my friend :frown: so i can workout b .


Find BD using pythagoras
Then write down BO
Then use the triangle HOB to find HO using trig
Original post by keerthan
i got the Length of OH As 9.02 i dont know if its right but im really stuck on Part b .


You need to halve your answer for BD, to find OB, before you carry on to finding OH.

For part (b), you can find the distance between O and the midpoint of one of the square's sides and then use SOHCAHTOA to find the angle the sloped planes make with the ground.
Reply 7
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keerthan
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thanks but im kind of stuck now
i found out that OB = 8.49 to 1 d.p) and then to find OH i need an angle so i was wondering what is OBH ? isit 28 degrees ?
(edited 9 years ago)
Original post by keerthan
Hello , thanks for ur replies guys but im kind of stuck now
i found out that OB = 8.49 to 1 d.p) and then to find OH i need an angle so i was wondering what is OBH ? isit 28 degrees ?


If you use the reply button people will know that you have replied to them and then they will respond :smile:


Yes
(edited 9 years ago)
Original post by keerthan
Hello , thanks for ur replies guys but im kind of stuck now
i found out that OB = 8.49 to 1 d.p) and then to find OH i need an angle so i was wondering what is OBH ? isit 28 degrees ?


8.49 contains 2 d.p. but yes, angle OBH is 28 degrees.
Reply 10
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keerthan
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Original post by TenOfThem
If you use the reply button people will know that you have replied to them and then they will respond :smile:


Yes


ahh im sorry , im new :frown: but okay i worked it out now :biggrin: thanks i got the answer as 4.51 (3 s.f) for OH ) but im really stuck at part b now as i have no clue where to start :frown:
Original post by keerthan
ahh im sorry , im new :frown: but okay i worked it out now :biggrin: thanks i got the answer as 4.51 (3 s.f) for OH ) but im really stuck at part b now as i have no clue where to start :frown:


I told you how to do part (b) above.
Original post by keerthan
ahh im sorry , im new :frown: but okay i worked it out now :biggrin: thanks i got the answer as 4.51 (3 s.f) for OH ) but im really stuck at part b now as i have no clue where to start :frown:


So far, so good

Do you know where the angle is in the diagram?
Reply 13
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keerthan
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Original post by TenOfThem
So far, so good

Do you know where the angle is in the diagram?

Umm im not really sure which angle i have to find but i know that OBH Is 28degrees and DOH is 90 degrees
Original post by keerthan
Umm im not really sure which angle i have to find but i know that OBH Is 28degrees and DOH is 90 degrees


Do you know which edge is in both planes?
Original post by keerthan
Umm im not really sure which angle i have to find but i know that OBH Is 28degrees and DOH is 90 degrees


The angle, for example, BCH makes with the ground is same as the angle the line connecting H with the midpoint of BC makes with the ground.
Reply 16
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keerthan
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Original post by TenOfThem
Do you know which edge is in both planes?

Nop im very confused lol first time doing an question like this
Reply 17
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keerthan
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Original post by HandmadeTurnip
The angle, for example, BCH makes with the ground is same as the angle the line connecting H with the midpoint of BC makes with the ground.


Umm i think im kinda getting it now. so am i trying to find out COH ?
Original post by keerthan
Umm i think im kinda getting it now. so am i trying to find out COH ?


No, that is a right angle
Original post by keerthan
Nop im very confused lol first time doing an question like this


Do you know what plane HCB is?

DO you know where the ground is?

Can you see an edge that joins them?

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