Find the area of the quadrilateral

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SUMMARY

The discussion centers on determining the area of a quadrilateral, specifically quadrilateral ABCD, using given dimensions. Participants highlight the impossibility of calculating the area without knowing the lengths of sides CD and AD, which affect the height of triangle ACD. The conversation emphasizes the use of basic geometric principles rather than advanced trigonometric functions, noting that angles B and D only sum to 180 degrees in cyclic quadrilaterals. Ultimately, the consensus is that without additional information, the area cannot be determined.

PREREQUISITES
  • Understanding of basic geometric principles, specifically the area of triangles.
  • Familiarity with properties of quadrilaterals and cyclic quadrilaterals.
  • Knowledge of sine and cosine rules in relation to angles.
  • Ability to visualize geometric shapes and dimensions.
NEXT STEPS
  • Research the properties of cyclic quadrilaterals and their angle relationships.
  • Study the formula for the area of a triangle, particularly in relation to base and height.
  • Explore methods for determining unknown dimensions in geometric figures.
  • Investigate the implications of missing dimensions in geometric calculations.
USEFUL FOR

Students, educators, and anyone interested in geometry, particularly those looking to understand the complexities of quadrilateral area calculations and the importance of known dimensions.

chwala
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Homework Statement
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Relevant Equations
sine rule
I was looking at this problem today, and i was trying to figure out its area with the given dimensions shown. First, is this even possible?...i later looked at the problem in detail and realized that i had missed out on some dimension that was given on the text.
Having said that, i would like to try and see if its possible to find the area of the quadrilateral with the given dimensions as indicated...i would nevertheless like to know whether this is possible. I will try look at it and share my working later...i will make use of sine, cosine rule and the angle property of parallelogram...

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There is not enough to determine where point ##D## is. The area of triangle ##ACD## could be anything.
 
PeroK said:
There is not enough to determine where point ##D## is. The area of triangle ##ACD## could be anything.
I was thinking of angle ##B##+##D##=##180^0##... this has to fix the point ##D## at some point...
 
chwala said:
I was thinking of angle ##B##+##D##=##180^0##... this has to fix the point ##D## at some point...
You can put D wherever you like. BCD is any triangle with a base of 5m.
 
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chwala said:
I was thinking of angle ##B##+##D##=##180^0##... this has to fix the point ##D## at some point...
Angles B and D would only add to 180 degrees for a cyclic quadrilateral.
 
Let me try and crack this tomorrow...sorry i have been a bit busy with work...let's see where i reach on this...i will try and find the dimensions of the quadrilateral...of course by use of the parallelogram property...then i may agree with you if its impossible...thanks Perok and Steve4Physics man!:cool:
 
Steve4Physics said:
Angles B and D would only add to 180 degrees for a cyclic quadrilateral.
Aaargh that's true...i overlooked that! let's see how far I go with this...
 
@chwala, what part of @PeroK's point escaped you? You don't need trig functions and such for this; it's 5th grade geometry:

##\mathrm{area~of}~\triangle = \frac 12(\mathrm{base}\times\mathrm{height})##.

In the illustration, increasing the lengths of CD and AD would increase the height. Since we don't know those lengths, we can't find the area of triangle ACD, and without knowing that area, we can't know the area of quadrilateral ABCD.
 
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sysprog said:
@chwala, what part of @PeroK's point escaped you? You don't need trig functions and such for this; it's 5th grade geometry:

##\mathrm{area~of}~\triangle = \frac 12(\mathrm{base}\times\mathrm{height})##.

In the illustration, increasing the lengths of CD and AD would increase the height. Since we don't know those lengths, we can't find the area of triangle ACD, and without knowing that area, we can't know the area of quadrilateral ABCD.
True, it's not possible to find the area...I just tried looking at it...cheers mate...
 
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