Trying to find interior of polygon with only sides and diagonals

[I need he1p]

So basically my mum is trying to solve a problem in which there is a trapezium-ish shape with its sides and diagonals measured and she is trying to figure out the interior angles of the four corners

 

[Deleted member 4993]

So basically my mum is trying to solve a problem in which there is a trapezium-ish shape with its sides and diagonals measured and she is trying to figure out the interior angles of the four corners

View attachment 31001

You have several triangles with 3 sides defined. Use laws of cosines for triangles and tell us what you find. For example, in triangle DAC

cos(DCA) = (AC² + CD² - DA²) / (2 * AC * CD)...................... and continue similarly

 

[blamocur]

So basically my mum is trying to solve a problem in which there is a trapezium-ish shape with its sides and diagonals measured and she is trying to figure out the interior angles of the four corners

View attachment 31002

Note that you have redundant data there, i.e. one diagonal and four sides are enough for the computations. In situations like this I usually take advantage of a redundancy to verify my measurements.

 

[I need he1p]

Wow thank you so much I can’t believe I didn’t spot that haha

Note that you have redundant data there, i.e. one diagonal and four sides are enough for the computations. In situations like this I usually take advantage of a redundancy to verify my measurements.

 

[I need he1p]

You have several triangles with 3 sides defined. Use laws of cosines for triangles and tell us what you find. For example, in triangle DAC

cos(DCA) = (AC² + CD² - DA²) / (2 * AC * CD)...................... and continue similarly

Thank you ???