Answer:
1680
Step-by-step explanation:
1680 is the answer
Answer: the answer should be 5
if you draw a right triangle 12 would be the line that goes up (A) and 13 would be the slanted line (C) so that leaves the bottom line to be C.
hope this helps!
Step-by-step explanation:

solution:
we know that ,
u.v = ΙuΙ ΙvΙcosθ
here,
θ =60° (since the given triangle is equilateral triangle)
u.v = ΙuΙ ΙvΙcos60°
= 1 x 1 x 1/2
u.v = 1/2
now, u.w = ΙuΙ ΙwΙcosθ
= ΙuΙ x cos(60x2)
u.w = -1/2