11 Emilio makes metal fences. He is making a fence using this design.
1.44 m
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1.8 m
.
The fence will need
3 horizontal metal pieces of length 1.8m
2 tall metal pieces of length 1.44 m
5 medium metal pieces
6 short metal pieces as shown on the diagram.
The heights of the tall, medium and short metal pieces are in the ratio 9:8:7
.
How many metres of metal in total does Emilio need to make the fence?

21.4 m

Step-by-step explanation:

Let x represent the sum of the tall metal, medium metal and short metal heights. Since the tall metal has a length of 1.44 m, and the ratio is in 9:8:7, hence:

(9/24) * x = 1.44

x = 3.84 m

For the medium metal pieces:

(8/24) * 3.84 = medium metal height

medium metal height = 1.28 m

For the short metal pieces:

(7/24) * 3.84 = short metal height

short metal height = 1.12 m

Total horizontal metal piece length  = 3 * 1.8 m = 5.4 m

Total tall metal piece length  = 2 * 1.44 m = 2.88 m

Total medium metal piece length  = 5 * 1.28 m = 6.4 m

Total short metal piece length  = 6 * 1.12 m = 6.72 m

Total length of metal = 5.4 + 2.88 + 6.4 + 6.72 = 21.4 m