The default secondary click behaviour on Trackpad in Yosemite has been set to “click with two fingers”. Listed below are the steps to change the Secondary click to Click in bottom right corner.
Step 1: Click Apple icon and select System Preferences from menu list.
Step 2: In the System Preferences screen, click Trackpad option.
Step 3: Under Point & Click tab, navigate to Secondary click option.
Step 4: Click the down arrow next to “Click with two fingers” and select “Click in bottom right corner” from the drop down list.