Find the area of the black region
Find the area of the black region accurate up to 3 decimal places. (A=?, a=20, b=10)Correct answers: 39
The first user who solved this task is Sanja Šabović.
#brainteasers #math #riddles
H.L. CallendarDied 21 Jan 1930 at age 66 (born 18 Apr 1863).Hugh Longbourne Callendar was an English physicist who was famous for work in calorimetry, thermometry and especially, the thermodynamic properties of steam. He published the first steam tables (1915). In 1886, he invented the platinum resistance thermometer using the electrical resistivity of platinum, enabling the precise measurement of temperatures. He also invented the electrical continuous-flow calorimeter, the compensated air thermometer (1891), a radio balance (1910) and a rolling-chart thermometer (1897) that enabled long-duration collection of climatic temperature data. His son, Guy S. Callendar linked climatic change with increases in carbon dioxide (CO2) resulting from mankind's burning of carbon fuels (1938), known as the Callendar effect, part of the greenhouse effect.« |