The Y-intercept is showing how many candy bars were sold in 2000 since x is every year after 2000 (hope that makes sense)
C=10, C=90°, B=30°, A+B+C=180°
A+30°+90°=180°⇒A=60°
cos30°=a/c
cos30°=a/10⇒a=cos30°*10
a<span>≃8.6602
c²=a²+b²⇒b²=c²-a²
b²=10²-8.6602²⇒b²=25
b=5
</span>
This should help
https://math.tutorvista.com/geometry/surface-area-of-a-trapezoidal-prism.html?view=simple
Just so you know, you can always use a calculator... or google which I know you have access to, considering you are on this site. Well, actually you could be using the brainly app but that's not the point. What I am trying to say is... you don't have to waste your points on questions like this! That's what Google is for :) Btw... your answer is 193