Area of a square = side length × side length s = a× a.

Area of parallelogram = base× height S=a×h

Area of triangle = base × height ÷2 S=a×h÷2.

Trapezoidal area = (upper bottom+lower bottom) × height ÷2 S=(a+b)×h÷2.

Garden area = pi (take 3. 14)× radius× radius s = pai× r× r.

Sector: π× radius× radius ÷360× central angle