(SAT prep) In △ABC, AB = BC =20, DE ≈ 9.28. Approximate BD.

BD = 5.36 ≈ 5.4

Step-by-step explanation:

length of line AB = length of line BC = 20, line DE ≈ 9.28

Since the length of line AB and line BC are equal, it follows that the length of line BD and line EC are also equal. Therefore, to get the length of line BD will be the difference between the length of lines BC and DE; the result is then divided by 2. The result gives us the length of line BD or line EC because the length of lines BD and EC are equal [BD = EC]

Mathematically,

BD = = =

BD = 5.36 ≈ 5.4

reduce the friction between its moving parts

step-by-step explanation:

in fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.