music: 70's Chart Toppers: Name The Artist: Amazing Grace?

Questions

[science and technology] what is the mathematical term used to describe the shape of a cell in a honeycomb?

[science and technology] how many degrees are there in a circle?

[science and technology] what is the name given to the green pigment in plants?

[science and technology] what is the instrument used to measure atmospheric pressure?

[science and technology] what colour spots has the common ladybird?