- Maths problem…
x = 20 degrees?
EDIT: Put in other symbols for the other unkown angles (y, z, etc.), then as sum of all angles in each triangle = 180, re-arrange equations to the form of e.g. y = x + 50 + 30 and then put that into the sum for a triangle that you’ve used ‘y’ in and solve to find x? I imagine there’s a clearer way of expressing that!Posted 4 years agohoneybadgerxSubscriber
Or, you can use the existing angles to give a set length to a particular side, and then calculate the relative lengths of the other sides, forming more triangle using 90 degrees where necessary, in order to calculate the angle that way. But that’d just be complicated 😀Posted 4 years ago
It’s non-soluble without a length as the angle changes dependent on the height of the major triangle.
Assume the top triangle is
and the complementary angles are c and x, so
we need to find a,b,c and x. Four equations and four unknowns;
Now you can solve these either as a matrix and take the inverse of the 4×4 or you can back substitute;
  [a]
 = 
  [c]
  [x]
Unfortunately the determinant of this matrix is zero, so there is no inverse. Hence no solution to the four equations. The problem is ill posed.
For back substitution;
b=140-c = 140-(130-x) = 10+x
a+b = a+(10+x) = 160 so a+x = 150
Hence you really only have three equations and four unknowns. That’s why it is on Facebook 😉
Maths is more fun than bike fitting 😉Posted 4 years ago
You are right, but it is ill-posed. Unless anyone spots an error in my alebra. Didn’t see one. four unknowns but only three independent equations. That means you can find x in terms of a ratio of another angle you can’t find. So you’ll have to draw it.
Ask yourself why it might be on Facebook 😉Posted 4 years agojambalayaSubscriber
At airport waiting for a flight so this is perfect :))
@Tired’s got it with the comment that the solution can be an equation, it doesn’t have to be a single number (“42” and all that 🙂 )
Will double check once on plane where I can write out the various equations. @Tired you kissed the chance to accuse everyone else of going off at a tangent … I’ll get my coatPosted 4 years ago
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