Habash al-Hasib al-Marwazi

Ahmad ibn 'Abdallah al-Marwazi, died 869) was a Persian astronomer, geographer, and mathematician from Merv in Khorasan, who discovered the trigonometric ratios tangent, and cotangent. Al-Biruni who cited Habash in his work, expanded his astronomical tables. possibly in Abbasid Samarra. The title "Habash" (Abbyssian) may refer to dark skin color.

Habash al-Hasib is the father of the astronomer Abu Ja'far ibn Habash.

The Book of Bodies and Distances Habash al-Hasib conducted various observations at the Al-Shammisiyyah observatory in Baghdad and estimated a number of geographic and astronomical values. He compiled his results in The Book of Bodies and Distances ,

Earth Earth's circumference: 20,160 miles (32,444 km) Earth's diameter: 6414.54 miles (10323.201 km) Earth radius: 3207.275 miles (5161.609 km)

Moon Moon's diameter: 1886.8 miles (3036.5 km) Moon's circumference: 5927.025 miles (9538.622 km) Radius of closest distance of Moon: 215,208;9,9 (sexagesimal) miles Half-circumference of closest distance of Moon: 676,368;28,45,25,43 (sexagesimal) miles Radius of furthest distance of Moon: 205,800;8,45 (sexagesimal) miles Diameter of furthest distance of Moon: 411,600.216 miles (662,406.338 km) Circumference of furthest distance of Moon: 1,293,600.916 miles (2,081,848.873 km)

Sun Sun's diameter: 35,280;1,30 miles (56,777.6966 km) Sun's circumference: 110,880;4,43 miles (178,444.189 km) Diameter of orbit of Sun: 7,761,605.5 miles (12,491,093.2 km) Circumference of orbit of Sun: 24,392,571.38 miles (39,256,038 km) One degree along orbit of Sun: 67,700.05 miles (108,952.67 km) One minute along orbit of Sun: 1129.283 miles (1817.405 km)