Somebody .. what is the area of the equilateral triangle? round to the nearest square centimeter.

for an equilateral triangle you need to know that:
- Sides are equal a = b = c (figure 1)
- Each angle is 60 degrees (figure 1)
- Height led from the top of the base of the triangle divide into two identical special right triangles on Measures angles 30,60,90 degrees. (figure 3)

triangle with angles : 30°,60° , 90°  is the length of the sides :
1 a = a  catheus (red)
2 b = a√3  catheus (red)
3 c = 2a  hypotenuse

the product of the hypotenuse of the triangle is the value of the surface of an equilateral triangle

P = a*b = (1/2*68cm*√3)*(1/2*68cm) = (34√3cm) * (34cm) = 1156√3cm²

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as soon as I add attachments - drawings

That they are numbers and related to each other.

Provide an equation