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In the figure the triangle is right triangle at *Y* and *N* is the foot of the perpendicular from *Y* to XZ. Given that XY=6 cm and XZ=10 cm. What is the length of XN

In the figure the triangle is right triangle at *Y* and *N* is the foot of the perpendicular-example-1
User Kwo
by
4.0k points

2 Answers

3 votes

Answer:

3.6cm

Explanation:

YZ = 10² - 6² = 8

sinX = 8/10 = 53.13º

cos 53.13º = XN/6

XN = 3.6cm

User Jisselle
by
4.1k points
2 votes

Answer:


\underline{ \underline{ \red{ \large {\tt{✧ G \: I \: V \: E \: N}}} }}:

  • XY = 6 cm , XZ = 10 cm


\underline{ \underline{ \purple{ \large{ \tt{✧ T \: O \: \: F\: I\: N\: D}}}}} :

  • Length of XN


\underline{ \underline{ \pink{\large {\tt{✧ S \: O \: L \: U\: T\: I \: O\: N}}}} }:

  • Let the length of XN be ' x ' & that of NZ be ' 10 - x '

In rt. XYZ :

  • Hypotenuse (h ) = 10 , Perpendicular ( p ) = YZ & Base ( b ) = 6

Using Pythagoras theorem:


\large{ \sf{p = \sqrt{ {h}^(2) - {b}^(2) } }}

Plug the values & then simplify!


\large{ \sf{YZ = \sqrt{( {10)}^(2) - {(6)}^(2) } }}


\large{ \sf{YZ = √(100 - 36)}}


\large{ \sf{YZ = √(64)}}


\large{ \sf{YZ = 8} \: cm} \:

In rt. YNZ ,

  • Hypotenuse = 8 cm , Perpendicular = YN , base = 10 - x

Using Pythagoras theorem :


\large{ \sf{ {p}^(2) = {h}^(2) - {b}^(2) }}


\large{ \sf{ {YN}^(2) = {8}^(2) - {(10 - x)}}}^(2)


\large{ \sf{ {YN}^(2) = 64 - \{ {(10)}^(2) - 2 * 10 * x + {(x)}^(2) \} }}


\large{ \sf{ {YN}^(2) = 64 - \{100 - 20x + {x}^(2) \}}}


\large{ \sf{ {YN}^(2) = 64 - 100 + 20x - {x}^(2) }}


\large{ \sf{ {YN}^(2) = 20x - {x}^(2) - 36}} \longrightarrow \: eq (i)

In rt. XYN ,

  • Hypotenuse = 6 , Perpendicular = YN , base = x

Using Pythagoras theorem :


\large{ \sf{ {p}^(2) = {h}^(2) - {b}^(2) }}


\large{ \sf{ {YN}^(2) = {(6)}^(2) - {(x)}}}^(2)


\large{ \sf{ {YN}^(2) = 36 - {x}^(2) \longrightarrow \: eq(ii) }}

Now , From Equation ( i ) & Equation ( ii )


\large{ \sf{20x - {x}^(2) - 36 = 36 - {x}^(2) }}


\large{ \sf{20x - \cancel{ {x}^(2) } - 36 = 36 - \cancel{ {x}^(2) }}}


\large{ \sf{20x = 36 + 36}}


\large{ \sf{20x = 72}}


\large{ \sf{x = 3.6}} cm

Hence, The length of XN is
\large{ \boxed{\red{ \bold{ \tt{3.6 \: cm}}}}}

[ Correct me if I am wrong ]

♨ Hope I helped! ♡

♪ Have a wonderful day / night ! ☃


\underbrace{ \overbrace{{ \mathfrak{Carry \: On \: Learning}}}}

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User Dave Huang
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4.3k points