noun
right circular cone
Technical geometry term for a cone whose axis is perpendicular to its circular base.
直円錐の体積は、底面の半径と高さから計算できる。
The volume of a right circular cone can be calculated from the radius of its base and its height.
円錐 is a general cone, while 直円錐 specifically refers to a right circular cone with a perpendicular axis.
Compound of 直 (choku, 'straight, right') and 円錐 (ensui, 'cone'), describing a cone with a right angle between the axis and the base.