I’d go with Physical geography.
Also known as geosystems, physical geography is one of the two major sub-fields of geography. It is part of the geographical study that focuses on examining landforms, soils, and water bodies. It also deals with the study of patterns in the natural environment such as, biosphere, geosphere, and hydrosphere.
First turn 18% to a decimal, which is .18, then multiply it by 450.
450 x .18 = 81
45 is 1/8 of a circle so then you take the 24 hours for a full one and divide by 8 24/8=3 3 Hours for a full rotation