Why are the lower parts of the glass panes in the windows of very old buildings found to be thicker than the upper parts?

Why the window glass of old buildings look milky?

Why is the window glass of the old building thick at the bottom ?

The lower part of a tent is of shape of a right circular cylinder , the height of which is 3.5 metres . The upper part of the the tent is of a shape of a right circular cone . If the total height of the tent be 9.5 metre and it its diameter of base be 5 metre , then how much quantity of tarpailin will be required to make 14 such tents ?

The lower part of a tent is in the form of a right circular cylinder whose height is 3.25metre. The upper part of the tent is in the form of a right circular cone. The total height of the tent is 9.25 metre and diameter of the base is 5 metre. How much tripol is required to make the tent?

A window of perimeter P (including the base of the arch) is in the form of a rectangle surrounded by a semi-circle. The semi-circular portion is fitted with the colored glass while the rectangular part is fitted with the clear glass that transmits three times as much light per square meter as the colored glass does. What is the ratio for the sides of the rectangle so that the window transmits the maximum light?

There is a solid iron - pillar in front of Anil's house , the lower part of which is of type of right circular cylinder and the upper part is of type of a right circular cone . The radii of their diameter of bases is 20 cm . If the height of the cylindricalpart be 2.8 metres and that of the conical part be 42 cm and if the weight of 1 cc iron be 7.5 gm , then what will be the weight of the pilar ?

The shape of the lower part of a solid object is like a hemisphere and the upper part like a right circular cone . If the surface area of the two parts be equal , then find the ratio of the length of radius and height of the cone .

A vertical pole with height more than 100 m consists of two parts, the lower being one-third of the whole. At a point on a horizontal plane through the foot and 40 m from it,the upper part subtends an angle whose tangent is 1/2 .Find the height of the pole.