The angle between the line x+2y−5=0  and the positive x-  axis is θ then the value of sinθ  is

The angle θ made by line with x-axis in positive direction is called inclination of the line.  The slope of the line ax+by+c=0 is m=−ab and θ=tan−1⁡−ab The slope of the line x+2y−5=0 is m=−ab=−12 If θ is inclination then tan⁡θ=−12,θ lies in the second quadrant.  Use right triangle the value for sin⁡θ=15