**Ncert Solutions for Class 9 Maths Chapter 13 pdf **covers the topic of **surface areas and volumes class 9** and the formulas to calculate the areas and volumes of Square, Rectangle, Triangle, Circle. To get more in-depth knowledge on **surface areas and volumes class 9** refer to **ncert solutions for class 9 maths chapter 13 pdf download**

**Area**

The space occupied by a two-dimensional flat surface. It is measure in square units.

Generally, Area can be of two types

(i) Total Surface Area

(ii) Curved Surface Area

**Total Surface Area**

Total surface area refers to area including the base(s) and the curved part.

** ****Curved surface area** (lateral surface area)

Refers to area of only the curved part excluding it’s base(s).

**Volume**

The amount of space, measured in cubic units, that an object or substance occupies.

**Surface area and volume all formulas**

The **Surface area and volume all formulas** are given below:

**Areas**

square = a^{2 }

rectangle = ab

parallelogram = bh

trapezoid = h/2 (b_{1}+ b_{2})

circle = *pi*r^{ 2}

ellipse = *pi*r_{1} r_{2}

- triangle = (1/2) b h
- equilateral triangle = (1/4)(3) a
^{2} - triangle given SAS = (1/2) a b sin C
- triangle given a,b,c = [s(s-a)(s-b)(s-c)] when s = (a+b+c)/2
**(Heron’s formula)** - regular polygon = (1/2) n sin(360°/n) S
^{2}

when n = # of sides and S = length from center to a corner

** ****Volumes**

cube = a^{3}

rectangular prism = a b c

irregular prism = **b**h

cylinder = **b**h = r^{2} h

pyramid = (1/3) **b**h

Cone = (1/3) **b**h = 1/3 r^{2} h

sphere = (4/3) r^{3}

ellipsoid = (4/3) *pi*r_{1} r_{2} r_{3}

**Surface Areas**

cube = 6 a^{2}

prism:

(lateral area) = perimeter(**b**) L

(total area) = perimeter(**b**) L + 2**b**

sphere = 4 r^{2}