Question

write atleast 20 formulas of areas of figures.i.e.,area of a triangle and so on..

Answer 1

area of rectangle length into breadth
area of square side in 2 side
area of parallelogram height into base
area of trapezium half into sum of parallel sides
area of triangle half into base into height
area of Rhombus half into diagonal 1 into diagonal 2
area of circle πrSquare
area of semicircle πrsquare divided by 2
Cube (surface)6 × side2
Sphere (surface)4 × pi × radius2

Cylinder (surface of side)perimeter of circle × height2 × pi × radius × height

Cylinder (whole surface)Areas of top and bottom circles + Area of the side2(pi × radius2) + 2 × pi × radius × height

Cone (surface)pi × radius × side
Torus (surface)pi2 × (radius22 - radius12)
Regular n-polygon(1/4) × n × side2 × cot(pi/n)
Ellipsepi × radius1 × radius2