#ncertmathshelpline cbse ncert maths solution class 9 ncert maths solution ,chapter 13 surface areas and volumes ,exercise 13.8 ,surface areas of cuboid and cube,surface area of a right circular cylinder,surface area of a right circular cone ,surface area of a sphere ,volume of a cuboid ,volume of cylinder,volume of a right circular cone ,volume of sphere. exercise 13.9 optional exercise of chapter 13 subscribe channel / @ncertmathshelpline