Hi,
I assume you are using Main Menu>Preprocessor>Meshing>Mesh>Areas>Mapped>3 or 4 sided.
Your geometrical area A1 seems quadrilateral. I'd recommend using Main Menu>Preprocessor>Meshing>Mesh>Areas>Mapped>By Corners and select the area and its corners .
Alternatively, you can use AMAP, AREA, KP1, KP2, KP3, KP4 command