acute

Everyday

1. (maths) An acute angle is less than 90 degrees, smaller than a right angle. tree →
2. Very serious or severe, like acute pain or an acute shortage. tree →
3. (medicine) Starting suddenly and lasting a short time, as opposed to chronic. tree →
4. Very sharp and good, about senses or the mind, like acute hearing. tree →

In the lessons

In maths: acute angle (under 90 degrees), acute triangle (all angles under 90). In health: acute pain, acute illness. In science about animals: acute sense of smell. Phrases: acute angle, acute triangle, acute shortage, acutely aware.

Examples

• An acute angle is smaller than a right angle. tree →
• All three angles in an acute triangle are less than 90 degrees. tree →
• Dogs have an acute sense of smell. tree →
• He was taken to hospital with acute stomach pain. tree →
• There is an acute shortage of water in the village. tree →
• Owls have acute hearing. tree →
• This one possessed the sense of hearing to a very high degree: so acute was this sense, that it was said he could hear the grass grow. tree →

Note

Maths: acute < 90 degrees, right = 90, obtuse between 90 and 180, reflex between 180 and 360. Exactly 90 is not acute. Medicine: acute (sudden, short) versus chronic (long-lasting). An "acute accent" is the mark on é.