4x = (130 - 2x) so x = 65/3
(3y + 40) + (130 -2x) = 180 because the angles are supplementary
plug in x
3y + 40 + 130 - 2(65/3) = 180
so 3y = 95/3
therefore y = 95/6
Let X represent the length of the chord.
By using Pythagoras' Theorem:
4^2 + (X/2)^2 = 15^2
(X^2)/4 = 209
X^2 = 836
X = 28.91
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