Need doing this and it'd be if you explained how you did it!

sinc=3/5

ab/bc=3/5

ac2= bc2 -ab2 ( use Pythagoras)

ac2=25-9

ac=4

tanc=ab/ac

=3/4 answer

cos A = 4/5

tan A = 4/3

Step-by-step explanation:

We are told that the sine of Angle A is 3/5.

The sine is defined as the ratio (opposite side) / (hypotenuse).

Here we can assign the value 3 to the length to the opposite side and the value 5 to the hypotenuse.  Since this triangle is a right triangle, the Pythagorean Theorem applies:

(opposite side)^2 + (adjacent side)^2 = (hypotenuse)^2.

To write the cosine of Angle A, which is defined as (adjacent side) / (hypotenuse), we need to find the length of the adjacent side:

| adjacent side | = √[ (hypotenuse)^2 - (opposite side)^2.

In this particular case,

| adjacent side | = +√[ 5^2 - 3^2 ], ior just 4.

Then:  cos A = 4/5

To write tan A:  Find the numerical ratio (opp side) / (adj side), which here is tan A = 3/4

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.