Find the length of red arc AB
Find the length of red arc AB (r1=1, r2=2). Express result to the accuracy of 3 decimal.Correct answers: 43
The first user who solved this task is Roxana zavari.
#brainteasers #math
Electric railway deviceIn 1895, black American inventor William B. Purvis was issued a patent for a "Magnetic Car Balancing Device." In his life, Purvis held other patents for electric railway devices (1894, 1897), and he also patented ten paper bag machines (1884-94). Other patents were issued to him for a bag fastener (1882), a hand stamp (1883) and a fountain pen (1890). |