Assertion : Pascal's law is the working principle of hydraulic lift.

Reason : $Pressure =\frac{Thrust}{Area}$

A hydraulic lift is an arrangement used to multiply the force. When a force is applied, hydraulic Pressure is transmitted in all direction. A pressure change at any point in a confined incompressible fluid is transmitted throughout the fluid such that the same change occurs everywhere. Thus, it works on the principle of Pascal's law. 

Pressure is calculated as ,

$Pressure = \frac{Force}{Area} or, Pressure = \frac{Thrust}{Area}$

Both are correct , but Reason is not the correct explanation for the Assertion.