Question

when we have to find curved surface area and total surface area?

Answer 1

Answer:

for which 3d shape?

please mark as brainlist

Answer 2

Answer:

Step-by-step explanation:

CURVED SURFACE AREA

About "Curved surface area"

Curved surface area of a solid is the measurement of outer area,where the extension of top and bottom portion wont be included.  

Curved surface area of cylinder:

If a rectangle revolves about one side and completes one full rotation, the solid thus formed is called a right circular cylinder. The above picture shows that how rectangle forms a right circular cylinder. In other words curved surface area can be simply said as CSA.

CSA of cylinder = 2 π r h

"r" and "h" stands for radius and height of cylinder.

Curved surface area of Sphere:

If we consider the shapes like sphere, both total surface area and CSA would be same.

Because in the shape sphere, we don't need any specific top portion or bottom portion (circles or any other shapes) as we have for cylinder

CSA of sphere = 4 π r²

Here "r" represents radius of the sphere.

Curved surface area of hemisphere:

CSA of hemisphere = 4 π r²

Curved surface area of Cone:

And for the shapes like cone, we don't have any specific shape at the top portion. But we have the circle at the base (bottom). So when we want to find the CSA of a cone, we need to find the area that exclude the extension of the bottom portion or base.In the top portion.

We don't need to exclude anything. Because there will be only one vertex at the top.So we don't have to exclude any thing at the top when we want to find CSA of cone.

CSA of cone = π r l  

Here "r" represents radius and "L" represents slant height of the cone.

Total Surface Area Defined

Surface area means all the area that you can see in two dimensions - this means the length and width. The surface area of a wall is everything you can paint. The surface area of a floor is everything you can walk on. So, the surface area of a rectangle, circle, triangle, or other shape is simply a measurement of everything within the lines of the shape. For a two-dimensional object, that's also its total surface area.

In three dimensions, like a cube, a sphere, or a pyramid, the surfaces can't all be seen at one time. Total surface area in that case means adding up the areas of all the surfaces. For a cube, that means adding up the surface area of all six sides. For a sphere like a baseball, you want to know how much area the leather casing measured.