I've added an image for illustrative purposes, where h is the height of the birdcage.
We can see that we'll need to use the pythagorean theorem which, when given the length of the diagonal and one of the perpendicular lengths of the triangle, is:

Substituting the information into this equation:

Therefore, the height of the birdcage is 12cm.
Answer:
regarder
Explanation:
acheter = to buy
regarder = to look at
travailler = to work
étudier = to study
Je regarde la télévision.
Bonjour,
2. Je suis revenu/e
3. Je suis mort/e
4. Je suis parti/e
5. ok
6. Elle s’est habillé/e
7. Nous nous sommes brûlés/ées
8. Vous vous êtes cachés/ées
Bonjour,
<u>GRAMMAIRE</u>
<em>A.</em>
correct
<em>B. </em>
1=D
2=E
3= B
4=C
5=A
<em>C.</em>
Correct
<em>D.</em>
<em>1. Est-ce que </em>tu as--<em>-----</em>
<em>2. Jacqueline </em>a-<em>--------------</em>
<em>3. Jacqueline et moi </em>nous avons---<em>--</em>
<em>4. Louis et Daniel </em>ont--<em>-----------</em>
<em>5. Je </em>n'ai--<em>--</em>
<em>E.</em>
<em>- </em><em>des</em><em> livres et </em><em>un </em><em>grand dictionnaire dans la salle de classe.</em>
<em>Il y a aussi </em>des <em>chaises,</em> une<em> horloge et</em> un<em> tableau blanc.</em>
<em>Il n'y a pas </em>de <em>fenêtres et il n'y a pas </em>d'<em>étudiants.</em>