Answer:
Tetragonal unit cell.
Step-by-step explanation:
A unit cell is the smallest part of a material which is formed by a well arranged lattice points. Some common types are; face centered, body center, tetragonal, cubic etc
Tetragonal unit cell has a square top and base, with rectangular sides. The internal angles are 
each, and consists of molecules, atoms, or ions (lattice points) arranged at each corners of the unit cell.
The crystal as described in the given question is a tetragonal unit cell.
Is the that the entire question?
Answer:
The solve of this equation is X = 4,06
Step-by-step explanation:
To solve this formula:
2 ( X² - 16) = 1
You must use the distributive law of multiplication, thus:
2X² - (16×2) = 1
2X² - 32 = 1
2X² = 1 + 32
X² = 33/2
X² = 16,5
X = √16,5
X ≈ 4,06
Thus, the solution of this equation is:
<em>X ≈ 4,06</em>
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I hope it helps!
Here's a diagram showing how to combine angles LDA (in red) and angle ADE (in blue). Hopefully it becomes a bit clearer why these two angles add up to line segment LE. Erase the shared segment DA if it helps show LE better.
See attached image below.
