Answer:
100 tiles
Explanation:
Each tile is an equilateral triangle with sides 6 cm in length, so the area of each tile can be found using the formula for the area of a triangle:
where b is the base and h is the height.
Since each side of the triangle is 6 cm, the base and height of the triangle are both 6 cm, so:
So each tile has an area of 18 cm².
To find the number of tiles needed to cover an area of 1800 cm², divide the total area by the area of each tile:
Therefore, Liz needs 100 tiles to cover an area of 1800 cm².