aI really had a wonderful summer holiday. I finished doing my homework on time and prepared for the new lessons. I visited my grandparents and spent a week with them. There I helped my parents with the housework and climbed the mountain with them. I do sports with my friends nearly every...
Anyone who can recall math classes will remember the first lessons of plane geometry that usually start with the Pythagorean theorem about right-angled triangles: a2+b2=c2. In spite of its name, the Pythagorean theorem was not discovered by Pythagoras. The earliest known formulation of the ...