Help, Trigonometry MATHS!!! (1 Viewer)

[Speed6]

Please include a drawn diagram on how to get started with the question please orI wouldn't know how you got from one point to another without relevant explanations with diagrams!

 

[Speed6]

Your aim is to find the area of that quadrilateral. Break it down so that you can calculate it

m9 I split it into 2 to form 2 triangles and label each as 1 and 2 respectively but I need a diagram to start me off because whenever I split it into triangles it overlaps the 2 angles...

 

[Speed6]

I've split it and formed 2 triangles respectively, I have cut through angles so do I half them both where I have?

 

[Speed6]

Urr.. what I think you do is to use the formula
A = 1/2 absinC

Keep the initial two triangles that you split up because you have the length of two sides. Thus, A1 = 1/2 x 5 x 2 x sin50

Now, use the fact that the overall length of the shape is 27m
This indicates that the remaining sides are 27 - (2+5) metres in length
so
A2 = 1/2 x (20) x sin100

Add A1 and A2 together, and that should give you the overall area of the shape

Ok thanks

 

[Speed6]

Joshmosh why did you delete your original post?

 

[Feynman]

Joshmosh why did you delete your original post?

Cause it's wrong

 

[Speed6]

Can anybody help me with this question then please?

 

[merrick]

what level is this

 

[BLIT2014]

I've split it and formed 2 triangles respectively, I have cut through angles so do I half them both where I have?

Looks like a sine rule or cosine rule problem..
From a brief glance..

 

[Speed6]

Bro I swear like 4 people have attempted to help me with this question but no one has actually got me on the right track :/.

Where's Drongonski when you need him.

 

[panda15]

Draw a line parallel to the base from the 130 degree angle to the other side. Then you have a triangle and trapezium that you can get the area from.

 

[Speed6]

Draw a line parallel to the base from the 130 degree to the other side. Then you have a triangle and trapezium that you can get the area from.

Once I get the area of the shape how would I then go to the next part of getting the volume as said by the question?

 

[panda15]

Once I get the area of the shape how would I then go to the next part of getting the volume as said by the question?

Multiply by 27.

 

[Joshmosh2]

Joshmosh why did you delete your original post?

My solution was wrong. The 27 is used at the end after you have found the area of the shape.

 

[Joshmosh2]

Sorry about the wrong solution, I will type up worked solutions right now.

This is how i worked it out:
http://imgur.com/kgAWciw
Is the answer right?

This is clearly not the efficient way to solve the Q.

 

[Joshmosh2]

Draw a line parallel to the base from the 130 degree angle to the other side. Then you have a triangle and trapezium that you can get the area from.

Um the problem that by using this method, you would have to find the value of the other leg of the trapezium to use the formula A = 1/2 h (a+b)

Even if you worked the area out, you will still be stuck with a triangle, with unknown sizes and angles

 

[Tugga]

LOL er guys, that shape is a trapezium, the diagram is dodgy

 

[Shinx]

What level of math is this? General, Mathematics, Ext 1, Ext 2 ?

 

[Speed6]

Maybe it's the authors fault?

Joshmosh, your answer was not far off as the answer for that question is 175 m^3.

Anyway thank you all for having a go at this challenging??? question my last resort for this question is now my maths teacher...

 

[Tugga]

Once you realise it's a trapezium it's fairly straightforward. Just drop perpendiculars to find the height and you can use trig to find the difference between top and bottom.