Why do we need to measure stuff

Modern society simply could not exist without measurement. Time, size, distance, speed, direction, weight, volume, temperature, pressure, force, sound, light, energy—these are among the physical properties for which humans have developed accurate measures, without which we could not live our normal daily lives.

to know the length/height of something

Explanation:

for example, say you wanted a pool, you want it to be big enough to swim around in so you'd want to know the length of the pool you're going to buy

we need the questions , i may then you.

the answers would be

the first one and the second one