Triangle XYZ is an isosceles triangle with right angle at Y. If XZ=12cm,find the length of the altitude from Y to XZ
Answers
Answer
6 cm
Explanation
(Refer attachment for figure)
Given, XYZ is an isoceles triangle, right angled at Y.
XZ = 12 cm
To find,
The length of altitude from Y to XZ
Since, XYZ is an isoceles triangle,
⇒ XY = YZ
Let, XY = YZ = a
Then, applying Pythagoras Theorem, we get
a² + a² = 12²
⇒ 2a² = 12²
Taking root on both sides.
a√2 = 12
⇒ a = 12/√2
Rationalising,
⇒ a = 6√2
Now, area of triangle = 1/2 × base × height
⇒ area of triangle XYZ = 1/2 × XY × YZ
⇒ area of triangle XYZ = 1/2 × 6√2 × 6√2
⇒ area of triangle XYZ = 36 cm²
Let the altitude from Y to XZ be YM
In that case, area of triangle XYZ = 1/2 × XZ × YM
But we know that area of triangle = 36 cm²
⇒ 1/2 × XZ × YM = 36
⇒ 1/2 × 12 × YM = 36
⇒ 6 × YM = 36
⇒ YM = 6 cm
Question :-- Triangle XYZ is an isosceles triangle with right angle at Y. If XZ=12cm,find the length of the altitude from Y to XZ ?
Solution (1) :--
❁❁ Refer To Image First .. ❁❁
Let , XY = YZ = a cm.
Using pythagoras Theoram in Rt∆XYZ now,
→ XY² + YZ² = XZ²
→ a² + a² = (12)²
→ 2a² = 144
→ a² = 72
→ a = 6√2 cm. = XY = YZ
Now, Area of Right ∆ = 1/2 * Base * Perpendicular = 1/2 * Hypotenuse * Length of altitude To Vertex.
Putting values and comparing their Area we get,
→ 1/2 * 6√2 * 6√2 = 1/2 * 12 * Altitude .
→ 36 * 2 = 12 * Altitude
→ Altitude = 72/12 = 6cm.
Hence, Length of the altitude from Y to XZ is 6cm.
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Solution (2) :--
After Finding the Sides of Right Angle ∆XYZ , we have now,
→ XY = YZ = 6√2 cm.
→ XZ = 12cm.
Let, XW = m cm.
Than, WZ = (12-m) cm. (As XZ is 12cm. )
Now, in Right Angle ∆ we know, That,
→ XY² = XW * XZ
Putting values here , we get,
→ (6√2)² = m * 12
→ m = 72/12 = 6cm.
So, WZ = (12-m) = 12-6 = 6 cm .
we have now, XW = WZ = 6 cm Each .
Again, in Right Angle ∆, we have ,
→ WY² = XW * WZ
putting values here now, we get,
→ WY² = 6 * 6
→ WY² = 6²
Square - root both sides ,
→ WY = 6 cm.
Hence, Length of the altitude from Y to XZ is 6cm.
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Solution (3) :---
when we Find XW = WZ = 6cm Above, with this we can say that,
→ Point W is the circumcentre of Right ∆XYZ. As we know that, circumcentre of Right angle ∆ divides Hypotenuse in 2 Equal Parts .
So,
→ XW , WZ and WY are circum-Radius of Circumcircle .
Hence, XW = WZ = WY = 6cm. Each .
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Equations are just the boring part of mathematics. I attempt to see things in terms of geometry.