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Source: various maths texts!

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Presentation on theme: "Source: various maths texts!"β€” Presentation transcript:

1 Source: various maths texts!
Strange Guys Source: various maths texts!

2 Strange Guys 900 π‘š 100 π‘š Not to scale β„Ž π‘š 350 π‘š Two tall vertical masts on horizontal, level ground have guy ropes tightly tethered to the other’s base. They cross at a point between them. How high above the ground do they cross?

3 Strange Guys β„Ž π‘₯ = π‘Ž 𝑑 and β„Ž π‘‘βˆ’π‘₯ = 𝑏 𝑑 π‘₯= β„Žπ‘‘ π‘Ž and π‘‘βˆ’π‘₯= β„Žπ‘‘ 𝑏
From similar triangles: β„Ž π‘₯ = π‘Ž 𝑑 and β„Ž π‘‘βˆ’π‘₯ = 𝑏 𝑑 Rearranging: π‘₯= β„Žπ‘‘ π‘Ž and π‘‘βˆ’π‘₯= β„Žπ‘‘ 𝑏 Adding gives: 𝑑= β„Žπ‘‘ π‘Ž + β„Žπ‘‘ 𝑏

4 Strange Guys 𝑑=β„Žπ‘‘ 1 π‘Ž + 1 𝑏 1=β„Ž π‘Ž+𝑏 π‘Žπ‘ So β„Ž= π‘Žπ‘ π‘Ž+𝑏 Or 1 β„Ž = 1 π‘Ž + 1 𝑏
π‘₯ 𝑑 𝑑= β„Žπ‘‘ π‘Ž + β„Žπ‘‘ 𝑏 𝑑=β„Žπ‘‘ 1 π‘Ž + 1 𝑏 1=β„Ž π‘Ž+𝑏 π‘Žπ‘ So β„Ž= π‘Žπ‘ π‘Ž+𝑏 Or 1 β„Ž = 1 π‘Ž + 1 𝑏 Notice that the distance between the masts is irrelevant to the question asked.

5 The guys cross 90 π‘š above the ground.
Strange Guys 𝑏 π‘Ž β„Ž 𝑑 For: π‘Ž=100 𝑏=900 β„Ž= (100) =90 The guys cross 90 π‘š above the ground.

6 Strange Guys Can you simply explain why the distance 𝑑 is irrelevant?
β„Ž 𝑏 π‘Ž 𝑑 Can you simply explain why the distance 𝑑 is irrelevant? Imagine the diagram was printed on a rubber sheet and then stretched parallel to the ground.

7 Strange Guys Can you simply explain why the distance 𝑑 is irrelevant?
𝑏 π‘Ž Can you simply explain why the distance 𝑑 is irrelevant? Imagine the diagram was printed on a rubber sheet and then stretched parallel to the ground. You can see that β„Ž is unaltered by the transformation. Note also that the ratio π‘₯:𝑦 is unaltered.

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9 RESOURCES

10 Strange Guys 900 π‘š 100 π‘š Not to scale β„Ž π‘š 350 π‘š Two tall vertical masts on horizontal, level ground have guy ropes tightly tethered to the other’s base. They cross at a point between them. How high above the ground do they cross? SIC_35

11 Strange Guys Strange Guys β„Ž β„Ž
Two tall vertical masts on horizontal, level ground have guy ropes tightly tethered to the other’s base. They cross at a point between them. How high above the ground do they cross? Strange Guys 108 π‘š 540 π‘š 350 π‘š β„Ž π‘š Not to scale SIC_35 Two tall vertical masts on horizontal, level ground have guy ropes tightly tethered to the other’s base. They cross at a point between them. How high above the ground do they cross? Strange Guys 110 π‘š 495 π‘š 360 π‘š β„Ž π‘š Not to scale SIC_35

12 Strange Guys Strange Guys β„Ž β„Ž
Two tall vertical masts on horizontal, level ground have guy ropes tightly tethered to the other’s base. They cross at a point between them. How high above the ground do they cross? Strange Guys 115 π‘š 414 π‘š 550 π‘š β„Ž π‘š Not to scale SIC_35 Two tall vertical masts on horizontal, level ground have guy ropes tightly tethered to the other’s base. They cross at a point between them. How high above the ground do they cross? Strange Guys 117 π‘š 390 π‘š 580 π‘š β„Ž π‘š Not to scale SIC_35

13 Strange Guys Strange Guys β„Ž β„Ž
Two tall vertical masts on horizontal, level ground have guy ropes tightly tethered to the other’s base. They cross at a point between them. How high above the ground do they cross? Strange Guys 120 π‘š 360 π‘š 455 π‘š β„Ž π‘š Not to scale SIC_35 Two tall vertical masts on horizontal, level ground have guy ropes tightly tethered to the other’s base. They cross at a point between them. How high above the ground do they cross? Strange Guys 126 π‘š 315 π‘š 215 π‘š β„Ž π‘š Not to scale SIC_35

14 Strange Guys Strange Guys β„Ž β„Ž
Two tall vertical masts on horizontal, level ground have guy ropes tightly tethered to the other’s base. They cross at a point between them. How high above the ground do they cross? Strange Guys 135 π‘š 270 π‘š 256 π‘š β„Ž π‘š Not to scale SIC_35 Two tall vertical masts on horizontal, level ground have guy ropes tightly tethered to the other’s base. They cross at a point between them. How high above the ground do they cross? Strange Guys 140 π‘š 252 π‘š 512 π‘š β„Ž π‘š Not to scale SIC_35

15 Strange Guys Strange Guys β„Ž β„Ž
Two tall vertical masts on horizontal, level ground have guy ropes tightly tethered to the other’s base. They cross at a point between them. How high above the ground do they cross? Strange Guys 144 π‘š 240 π‘š 452 π‘š β„Ž π‘š Not to scale SIC_35 Two tall vertical masts on horizontal, level ground have guy ropes tightly tethered to the other’s base. They cross at a point between them. How high above the ground do they cross? Strange Guys 150 π‘š 225 π‘š 555 π‘š β„Ž π‘š Not to scale SIC_35

16 Strange Guys Strange Guys β„Ž β„Ž
Two tall vertical masts on horizontal, level ground have guy ropes tightly tethered to the other’s base. They cross at a point between them. How high above the ground do they cross? Strange Guys 165 π‘š 198 π‘š 200 π‘š β„Ž π‘š Not to scale SIC_35 Two tall vertical masts on horizontal, level ground have guy ropes tightly tethered to the other’s base. They cross at a point between them. How high above the ground do they cross? Strange Guys 171 π‘š 190 π‘š 533 π‘š β„Ž π‘š Not to scale SIC_35


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