One meaning of forceful is all about physical strength: The forceful throw carried the football past the goalposts. Another way to be forceful is to be emphatic or vehement: The child's forceful refusal to go to bed could not be ignored by the sleepy babysitter. Forceful literally means full of force, and force comes from the Latin fortis, strong, firm, or steadfast.
In addition to being the 18th letter of the Greek alphabet, sigma also means 'sum' and 'deviation' in the mathematics world. Learn what each symbol looks like and how each formula works. High School Precalculus: Homework Help Resource / Math Courses.
Geometry is one of the classical disciplines of math. Roughly translating in Greek as Earth Measurement, it is concerned with the properties of space and figures. It is primarily developed to be a practical guide for measuring lengths, areas, and volumes, and is still in use up to now.