Q1. By how many % will the s.a of the cube increase if each side is doubled?
Q2. A circle of radius 7cm is divided into two sectors by cutting 120 degree sector from the centre.The 2 sectors are used to form 2 cones of l=7cm, find the ratio of bigger cone to smaller cone?
Q3. If a=csa, b=tsa, v=vol then express v in terms of a & b. (for a cuboid)
Q4. Find 1/[(2^2)-1]+1/[(4^2)-1]+1/[(6^2)-1]......1/[(20^2)-1]
Show the statements an solutions as well.
Thanks
Well the area of a square is where s is the length or height.
And a cube has 6 squares on it's surface, so
So if we double the size of our width, height, and length, then we still have a cube, as they are all equal to 2s
So we can plug this new value for length into our formula:
And note that our formula earlier was that So we can substitute this value in:
So we can see that the surface area of a cube with a side of 2s is 4 times larger than the surface area of a cube with a side of s.
Based on the wording in the question, I think they want you to say "4 is 3 more than 1, so the surface area increases 300%"