2. Square area = side length × side length formula: S = a× a.

3. area of rectangle = length× width formula: S= a×b

4. area of parallelogram = base× height formula: S= a×h

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

6. Sum of internal angles: sum of internal angles of triangle = 180 degrees.

7. cuboid volume = length× width× height formula: V=abh

8. cuboid (or cube) volume = bottom area × height formula: V=abh.

9. Volume of cube = side length × side length × side length formula: V=aaa.

10. circumference of a circle = diameter × π formula: l = π d = 2π r.

1 1. Area of circle = radius× radius× π formula: s = π R2.