Which of these was an invention that showed Europeans the advancements of the united states in the 1800s

3.a

4.d

5.b

6.b

7.c

8.a

9.d

10.a

answer: this problem has only trivial solutions, with all points on the same line. x=5 or x=7/5.

step-by-step explanation:

there are three triangles, and three unknowns: x, y=length of middle segment, and z=cos(angles marked with red arc).

we need

and law of cosines,

the three equations are

see attached image for solution.