To determine the height of the tree, considering that you want to leave a 20-centimetre space between the top of the tree and the ceiling, follow these steps:
1. Identify the total height available for the ceiling:
The ceiling height is given as 210 centimetres.
2. Determine the required space between the tree and the ceiling:
You want to leave a 20-centimetre space.
3. Subtract the space from the total ceiling height:
To find how tall the tree can be, subtract the 20 centimetres of space from the total ceiling height. This means:
[tex]\[
\text{Tree height} = \text{Ceiling height} - \text{Space with ceiling}
\][/tex]
Substituting the values:
[tex]\[
\text{Tree height} = 210 \, \text{cm} - 20 \, \text{cm}
\][/tex]
4. Perform the subtraction:
[tex]\[
210 \, \text{cm} - 20 \, \text{cm} = 190 \, \text{cm}
\][/tex]
Therefore, the tree must be 190 centimetres tall.
