Answer :

To determine the number of sides of a convex polygon given that the sum of its interior angles is 1800°, follow these steps:

1. Recall the formula for the sum of the interior angles of a polygon:
The sum of the interior angles of a polygon with [tex]\( n \)[/tex] sides can be calculated using the formula:
[tex]\[ \text{Sum of interior angles} = (n - 2) \times 180^\circ \][/tex]
where [tex]\( n \)[/tex] is the number of sides of the polygon.

2. Set up the equation:
We are given that the sum of the interior angles is 1800°. So, plug the given sum into the formula:
[tex]\[ (n - 2) \times 180 = 1800 \][/tex]

3. Solve for [tex]\( n \)[/tex]:
To find the number of sides [tex]\( n \)[/tex], we need to solve the equation for [tex]\( n \)[/tex].
[tex]\[ (n - 2) \times 180 = 1800 \][/tex]
Divide both sides of the equation by 180 to isolate [tex]\( n - 2 \)[/tex]:
[tex]\[ n - 2 = \frac{1800}{180} \][/tex]

4. Simplify the right-hand side:
[tex]\[ n - 2 = 10 \][/tex]

5. Solve for [tex]\( n \)[/tex] by adding 2 to both sides:
[tex]\[ n = 10 + 2 \][/tex]
[tex]\[ n = 12 \][/tex]

Therefore, the convex polygon with an interior angle sum of 1800° has [tex]\(\boxed{12}\)[/tex] sides.