Question

if three angels of a quadrilateral are 45 degree , 75 degree and 140 degree, find the fourth angle.

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Answer 1

In a quadrilateral, the sum of all the angles = 360.

Let the forth angle be ‘y’

Then,
45 + 75 + 140 + y = 360
260 + y = 360
y = 360 - 260
y = 100.

Therefore, forth angle = 100.