Sometimes a window may be in the perfect location on your Mac screen, but it’s too small or too large for what you want to do at that moment. In that case, you need to resize the window. To change the size of a window, follow these steps:
Move the pointer over the resize corner in the bottom-right corner of the window.
Hold down the left mouse button and drag the mouse.
The window grows or shrinks as you drag the mouse.
Release the left mouse button when you’re happy with the new size of the window.