(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

I have this arrow head geometry question (Please see diagram). I know L1, L2 and L3, angle B and the constant k (notice how the corner angle is equal to k * t2). I don't know t1 and t2. I'm pretty sure I have enough constraints, I'm just having trouble finding the right ones to use. Note that the arrow head is not symmetric so the top edge length is not equal to L3.

2. Relevant equations

Knowns:

L1

L2

L3

B

k

unknowns:

t1

t2

3. The attempt at a solution

The sum of the interior angles gives me one equation:

360 = t1 + t2+ 180 - t2 + t2 + k*t2 + B

B = 180 - t1 - t2 - kt2

Now I tried using the lengths and forming some equations using the cosine rule. I split the arrow head down the middle (gaining a length Lm), so I have

Lm^2 = L1^2 + L3^2 - 2*L1*L3*cos(t1)

but then I don't have the top edge as I mentioned, so I can't really equate this to anything.

I'm kind of stumped, any help would be appreciated!

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# Homework Help: Geometry question

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