Answer:
That would be the side-side-side (SSS) postulate, which states that if all the sides of a triangle are in a fixed ratio to all the corresponding sides of another triangle, then the two triangles are said to be congruent.
Step-by-step explanation:
Looking at triangles ABC and DEF, we notice that:

since

Let me know if you have further questions.
Answer:

Step-by-step explanation:
(g o h)(5) = g(h(5))
h(5) = 5-7
plug in h(5) where you have x.
g(h(5)) = 
Ernie spend 6hrs. × his 3 sisters
so, 6×3=18
18hours in total.