What does x = and why and how does that number come out

More algebra pretending to be geometry.  These questions should be banished from the planet.

A transversal across parallel lines generates the usual congruent and supplementary angles; here our pair are supplementary, adding to 180 degrees.  Geometry done.

(2x + 12.8) + 117.6 = 180

2x = 180 - (12.8 + 117.6) = 49.6

x = 49.6/2 = 24.8

24.8

HOPE U GET IT

step-by-step explanation:

there is a formula i can give you:

it is r^2*n*sin(360/n) divided by 2 where r represents the "radius" and n is the number of sides.

plug them in:

(10sqrt(3))^2*6*sin(360/6) divided by 2

100*3*6*sin(60) divided by 2

900*sin(60)

900*sqrt(3)/2

450*sqrt(3)

approx is 779.4 cm^2