## Important Surface Area Formulas

Area is the quantity that expresses the extent of a two-dimensional figure or shape, or planar lamina, in the plane. Surface area is its analog on the two-dimensional surface of a three-dimensional object. Area can be understood as the amount of material with a given thickness that would be necessary to fashion a model of the shape, or the amount of paint necessary to cover the surface with a single coat.

In civil engineering area calculations are very important for construction works, because if we do not have area surface than we are not able to find out the volume of any object.

We will give you below surface area formulas

1: Area of Square shape =  S2   ,  where S = Side

2: Area of rectangle   = a x b  ,   where b = base and h = height

3:  Area of parallelogram = b x h    ,  where b = base and h = vertical height

4: Area of trapezoid =  (1/2) * (a + b) * h,         where a =base 1, b = base 2, and h = vertical height

5:  Area of Circle = pi r 2       ,            where r = radius

6: Area of Triangle =  (1/2) b h       ,      where b = base and h = height

7: Area of Ellipse  =  pi r1 r2      ,               Where   1 = radius of major axis and 2 = area of minor axis

8: Area of regular polygon = (1/2) n sin(360°/n) S

If the  n = # of sides and S = length from center to a corner than we have to use the above formula.

For Irregular shape we use the Heron’s formula to find out the area of surface

Area of Irregular shape = A =   √s(s-a)(s-b)(s-c)] when s = (a+b+c)/2

Here , Here is     S  = a + b + c / 2           Here is in given figure. Image resource

Heron’s formula is named after Hero of Alexendria, a Greek Engineer and Mathematician in 10 – 70 AD. You can use this formula to find the area of a triangle using the 3 side lengths.Therefore, you do not have to rely on the formula for area that uses base and height. This formula is very important for civil engineers when they want to find out the irregular shape area. We hope that these surface area formulas will help you in your further work