Three parallel chords of a circle have lengths 2,3,4 units and subtend angles `alpha,beta,alpha+beta` at the centre, respectively `(alphaltbetaltpi),` then find the value of `cosalpha`

Explanation

To solve the problem, we need to find the value of \( \cos \alpha \) given three parallel chords of lengths 2, 3, and 4 units that subtend angles \( \alpha, \beta, \) and \( \alpha + \beta \) at the center of a circle, respectively.

### Step-by-Step Solution:

1. **Understanding the Geometry**:
- We have a circle with center \( O \).
- Let the lengths of the chords be represented as follows:
- Chord \( AB \) of length 4 subtends angle \( \alpha + \beta \).
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