[Christophicus]

If anyone could help me with part d I'd be grateful.
A diagram would be useful as I can't picture this at all.

d) Hence or otherwise, calculate the perpendicular distance from B to the line L.

Why is it this?




Not this?


The question calculates the distance using the first diagram which I didn't realise. The question specifies perpendicular from B to line L, not perpendicular from line L to B.

If someone could clear this up, I'd be grateful.

[Malik]

You just found out angle <LAB on part (c).
<LAB=35
Part (a) you worked out distance AB
AB=√11

You know its a right angled triangle so just apply the Sine rule:

sin35/BL=sin90/√11
√11sin35=BLsin90
√11sin35=BL
BL=1.9

[Christophicus]

Originally Posted by Malik

You just found out angle <LAB on part (c).
<LAB=35
Part (a) you worked out distance AB
AB=√11

You know its a right angled triangle so just apply the Sine rule:

sin35/BL=sin90/√11
√11sin35=BLsin90
√11sin35=BL
BL=1.9

Sorry, I still don't understand.
This question is really badly worded.
If you see my last diagram, the triangle might not be right angled.
Where is the perpendicular line taken from?

[Malik]

Originally Posted by Widowmaker

Sorry, I still don't understand.
This question is really badly worded.
If you see my last diagram, the triangle might not be right angled.
Where is the perpendicular line taken from?

I understand what your saying, but am just as lost as you on it. In order to get there required answer you are to assume its perpendicular at L.

Or it could mean that it should be perpendicular at both sides meaning both your diagrams are technically correct.

I am not to satisfied with this either now, if you find out an answer get back to me.

[Christophicus]

Originally Posted by Malik

I understand what your saying, but am just as lost as you on it. In order to get there required answer you are to assume its perpendicular at L.

Or it could mean that it should be perpendicular at both sides meaning both your diagrams are technically correct.

I am not to satisfied with this either now, if you find out an answer get back to me.

You can't assume that OB // L

--------------

Taking the perpendicular from line L you get the right answer.
The question is poorly phrased as it asks you to measure the perpendicular from B to line L. I think i'm misunderstanding the wording more than anything else.

[Malik]

Originally Posted by Widowmaker

You can't assume that OB // L

True, consider that question just says "perpendicular distance from B to the line l" . Point B not the line OB , so I am not sure whether you can assume that OB is perpendicular to BL.

[Christophicus]

Originally Posted by Malik

True, consider that question just says "perpendicular distance from B to the line l" . Point B not the line OB , so I am not sure whether you can assume that OB is perpendicular to BL.

yh that makes sense. Thanks.