Ram asked Kiran to find the ‘surface area’ of a flower vase. What does Kiran need to do?
Ram asked Kiran to find the ‘surface area’ of a flower vase. What does Kiran need to do?
This question is crucial because it connects area a 2-D quantity to 3-D objects. 3-D objects also have an area. What is it?
Consider a plane piece of paper. It has a certain 2-D area. Now fold this piece of paper. What do I get? I get a 3-D object on folding a 2-D paper. The area of paper still remains the same. This area is now able occupy space as a 3-D object. How? The 2-D plane has now become what can be called a ‘surface’ in 3-D. The area of folded paper has now become the area of the surface. This is called ‘surface area’.
How do I find surface area? Surface area is the area of surface of a 3-D object which is visible to the eye. One way to perceive surface area is to look at surface area as the area of surface of 3-D object that I can paint.
So how can Kiran find surface area of the flower vase? One way has already given. Kiran can paint the entire surface of flower vase. He should measure what quantity of paint has been used. He should now use same quantity of paint to paint on a 2-D surface. By measuring area of 2-D surface covered Kiran can find area of paint used in 2-D. This is nothing but area of surface painted in 3-D. This is nothing but surface area of vase.
This question is crucial because it connects area a 2-D quantity to 3-D objects. 3-D objects also have an area. What is it?
Consider a plane piece of paper. It has a certain 2-D area. Now fold this piece of paper. What do I get? I get a 3-D object on folding a 2-D paper. The area of paper still remains the same. This area is now able occupy space as a 3-D object. How? The 2-D plane has now become what can be called a ‘surface’ in 3-D. The area of folded paper has now become the area of the surface. This is called ‘surface area’.
How do I find surface area? Surface area is the area of surface of a 3-D object which is visible to the eye. One way to perceive surface area is to look at surface area as the area of surface of 3-D object that I can paint.
So how can Kiran find surface area of the flower vase? One way has already given. Kiran can paint the entire surface of flower vase. He should measure what quantity of paint has been used. He should now use same quantity of paint to paint on a 2-D surface. By measuring area of 2-D surface covered Kiran can find area of paint used in 2-D. This is nothing but area of surface painted in 3-D. This is nothing but surface area of vase.
