Letter: S=ab

Length of rectangle = area ÷ width a=S÷b

Width of rectangle = area ÷ length b=S÷a

2, the square area = side length x side length

Letter means: S= a?

3. Area of parallelogram = bottom × height

Letter: S=ah

Height of parallelogram = area/base h=S÷a

Base of parallelogram = area ÷ height a=S÷h

4. Area of triangle = base × height ÷2

Letter: S=ah÷2

Height of triangle = 2× area ÷ base H = 2s÷ a.

The base of triangle = 2× area ÷ height A = 2s ÷ h.

5. Trapezoidal area = (upper bottom+lower bottom) × height ÷2

Letter: s = (a+b) h÷ 2.

Height of trapezoid = 2× area ÷ (upper bottom+lower bottom) h=2S÷(a+b)

Upper bottom of trapezoid = 2× area ÷ height-lower bottom a=2S÷h-b

Trapezoidal bottom = 2× area ÷ height-upper bottom b = 2s ÷ h-a.