2. Square area = side length × side length? S=a2 .

3. parallelogram area = bottom × height? S = ah.

4. Triangle area = base × height ÷2? S=ah÷2 .

5. Trapezoidal area = (upper bottom+lower bottom) × height ÷2? s =(a+b)h \2 .

6. The area of the circle = π× the square of the radius? S=πr2 .

7. lateral area of cylinder = bottom circumference x height? S=Ch .