altitude

Everyday

1. Altitude is how high something is above the level of the sea or above the ground, as for a plane, mountain or town. tree →
2. (maths) In a triangle, the altitude is the line straight down from a corner to the opposite side, at a right angle; its length is the height. tree →

In the lessons

In geography and science altitude tells how high a place or plane is; air gets thinner and colder at high altitude. In maths it is the height of a triangle, used in area = half × base × height. Phrases: «at high altitude», «gain altitude», «lose altitude», «altitude sickness».

Examples

• The plane flew at an altitude of 10,000 metres. tree →
• At high altitude it is harder to breathe. tree →
• The pilot began to lose altitude before landing. tree →
• Some climbers get altitude sickness. tree →
• Draw the altitude of the triangle from the top corner. tree →
• The town sits at an altitude of 2,000 metres above sea level. tree →

Note

Usually uncountable for the idea («at altitude»), countable for values («different altitudes»). Altitude is height above sea level; «height» can be from any base. Maths: the altitude meets the base at a right angle; it is not the slanted side.

In Jewish tradition

In geography and science altitude tells how high a place or plane is; air gets thinner and colder at high altitude. In maths it is the height of a triangle, used in area = half × base × height. Phrases: «at high altitude», «gain altitude», «lose altitude», «altitude sickness».

Examples

• On page 16 we read as follows: "All his (Gods) creation, and every minutest part thereof, participates of two most essential forms : the line 1 the symbol of the altitude, and the circle 0 the symbol of the horizon. (Mordell, The Origin of Letters and Numerals according to Sefer Yetzirah (1914)) tree →

Note

Usually uncountable for the idea («at altitude»), countable for values («different altitudes»). Altitude is height above sea level; «height» can be from any base. Maths: the altitude meets the base at a right angle; it is not the slanted side.