The problem asks to find the size of angle $x$ given that the angles $20^\circ$, $x$, and $65^\circ$ lie on a straight line.

1. Problem Description

The problem asks to find the size of angle $x$ given that the angles $20^\circ$, $x$, and $65^\circ$ lie on a straight line.

2. Solution Steps

The sum of angles on a straight line is $180^\circ$.

Therefore, we have the equation:

$20^\circ + x + 65^\circ = 180^\circ$

Combine the known angles:

$85^\circ + x = 180^\circ$

Subtract $85^\circ$ from both sides of the equation to isolate $x$:

$x = 180^\circ - 85^\circ$

$x = 95^\circ$

3. Final Answer

The size of angle $x$ is $95^\circ$.