Answer:
Emilio will need 42 metres length of garland to decorate the length of the ceiling.
Step-by-step explanation:
Step 1: Determining the length of the ceiling
The Width of ceiling = 9 m
The Diagonal of ceiling = 15 m
The Length of the ceiling = y m
The width, diagonal and length of the ceiling forms a right-angle triangle with the diagonal as the hypotenuse
From Pythagoras theorem: 15² m² = 9² m² + y²
y² = 225 m² - 81 m²
y² = 144 m²
Take square root of both sides
y = 12 m
Length of the ceiling = 12 m
Step 2: Determining the perimeter of the ceiling
Perimeter of the ceiling = 2 ( length + width)
Perimeter of the ceiling = 2 (12 + 9) m = 2 × 21 m
Perimeter of the ceiling = 42 m
Therefore, Emilio will need 42 metres length of garland to decorate the length of the ceiling.
