Files attached.

Picture 1:
The formula to find an angle between any two vectors is:
𝑣⃗ . 𝑤
⃗⃗⃗
cos(𝜃) =
|𝑣⃗| ∗ 𝑤
⃗⃗⃗|
For this question we need to calculate the angle between each one of the vectors:
Angle between ab => cos(𝜃) =
Angle between ac => cos(𝜃) =
Angle between ad => cos(𝜃) =
Angle between ag => cos(𝜃) =
Angle between bc => cos(𝜃) =
Angle between bd => cos(𝜃) =
Angle between bg => cos(𝜃) =
Angle between cd => cos(𝜃) =
Angle between cg => cos(𝜃) =
Angle between dg => cos(𝜃) =

(a)
(b)
(c)
(d)

5 · 1 + 1 · 5 + (−1) · 6 = 5 + 5 − 6
√25 + 1 + 1 ∗ √1 + 25 + 36
−5 − 5 − 1

=> 𝜃 = 0.407 𝑟𝑎𝑑

√25 + 1 + 1∗√1 + 25 + 1
5 + 0.2 – 0.2

√25 + 1 + 1 ∗ √1 + 0.04 + 0.04
5+5+1

−1 − 25 + 6
√1 + 25 + 36∗√1 + 25 + 1

=> 𝜃 = 0.488 𝑟𝑎𝑑

1 + 1 + 1.2
√1 + 25 + 36∗√1 + 0.04 + 0.04
1 + 25 – 6
√1 + 25 + 36∗√1 + 25 + 1

=> 𝜃 = 0.39 𝑟𝑎𝑑

=> 𝜃 = 0.488 𝑟𝑎𝑑

−1 − 1 + 0.2
+
25
+
1∗√1 + 0.04 + 0.04
√1
−1 − 25 − 1

=> 𝜃 = 0.9259 𝑟𝑎𝑑

=> 𝜃 = 407 𝑟𝑎𝑑

√25 + 1 + 1 ∗ √1 + 25 + 1

√1 + 25 + 1∗ √1 + 25 + 1

=> 𝜃 = 0.0977 𝑟𝑎𝑑

𝜃 = −0.33 𝑟𝑎𝑑

=> 𝜃 = −1 𝑟𝑎𝑑

1 + 1 − 0.2
√1 + 0.04 + 0.04∗ √1 + 25 + 1

=> 𝜃 = 0.33 𝑟𝑎𝑑

None of the vectors have angle equal to 90° or 270°, so the answer is none.
The only ...