Question

Find the value of y if 140°, y and 150° are on a straight line.

Answer 1

If angles lie on a straight line then their sum is 180° .

$140+y+150=180\\y+290=180$

So from above equation we can conclude that the sum of y and 290 is greater then 180.

$y=180-290\\y=-110$

And also angles cannot be negative.

So, these pair of angles cannot lie on a straight line.