15PTS PLEASE HELP ASAP!
(dont write random answers pls)
look at the pic attached:

Triangle RST is an equilateral triangle.

Step-by-step explanation:

All three sides of the triangle are of equal length, therefore, because an isosceles triangle is when 2 sides of the triangle are the same length, a scalene triangle being when all sides are of different lengths, and a right triangle having a right angle (a 90 degree angle), this only leaves equilateral, all three sides being the same length, like in the triangle shown.

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.