Angles on a straight line add up to 180&deg;.<br><br>
&bull; Read the two angles given on the straight line from the diagram<br>
&bull; The missing angle a and the given angles together form a straight line<br>
&bull; Angle a = 180&deg; − sum of given angles on that line<br>
&bull; Angle a = 180&deg; − 85&deg; = 95&deg;<br><br>
Final Answer: 95