A circle is centered on point B. Points A, C and D lie on its circumference. Pro
If ZABC measures 40°, what does ADC measure?

m∠ADC = 20°

Step-by-step explanation:

A circle B has points B, C and D on the circumference.

m∠ABC = 40° [Cntral angle]

Since measure of the central angle is double of the inscribed angle by the arc

m∠ABC = 2(m∠ADC)

Here ∠ABC = Central angle

and ∠ADC = Inscribed angle

40° = 2(m∠ADC)

m∠ADC =

              = 20°

Therefore, measure of angle ADC is 20°.

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.