side length of square =4
side length of cube=3
hence the correct statement is,
the side length of the cube is less than the side length of the square
In the balanced reaction
2 Fe + O₂ → 2 FeO
2 moles of iron (Fe) react with 1 mole of molecular oxygen (O₂) to produce 2 moles of iron oxide (FeO). The ratio of Fe to FeO is 1-to-1, so if one starts with 42.4 mol of Fe, one will end up with the same amount of FeO, 42.4 mol.
Look up the molar mass of Fe and O:
• Fe = 55.845 g/mol
• O = 15.999 g/mol
Then the molar mass of FeO is approximately 71.835 g/mol, and so the mass of 42.4 mol of FeO is
(42.4 mol) × (71.835 g/mol) ≈ 3050 g
You can use a tangent:

We have opposite = 17 and adjacent = x.

substitute:
cross multiply
multiply both sides by √3

divide both sides by 3

Use the Pythagorean theorem:

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Other method.
triangle.
The sides are in the ratio 
Therefore

1st angle = 2 * 2nd angle
3rd angle = 2nd angle + 80
1st angle = 2x
2nd angle = x
3rd angle = 80 + x
2x + x + 80 + x = 180
4x = 100
x = 25
1st angle = 50
2nd angle = 25
3rd angle = 105
55 - 3 = 52
52 - 3 = 49
49 - 3 = 46
46 - 3 = 43
43 is your answer