document.write( "Question 1210470: Find the perimeter of triangle XYZ.\r
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document.write( "YZ = 10, YP = 6, XQ = 4, XP = 8, PQ = 7 \n" );
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Algebra.Com's Answer #852802 by CPhill(2189) You can put this solution on YOUR website! This problem is solvable by using the property of **tangents drawn from an external point to a circle**.\r \n" ); document.write( "\n" ); document.write( "The perimeter of $\triangle \text{XYZ}$ is **$28$**.\r \n" ); document.write( "\n" ); document.write( "---\r \n" ); document.write( "\n" ); document.write( "## 📐 Tangent Segment Theorem\r \n" ); document.write( "\n" ); document.write( "The key geometric principle here is the **Tangent Segment Theorem**: If two tangent segments are drawn to a circle from the same external point, then the segments are equal in length.\r \n" ); document.write( "\n" ); document.write( "In the provided figure, the inscribed circle (incircle) is tangent to the sides of $\triangle \text{XYZ}$ at points $\text{P}$, $\text{Q}$, and a third point, let's call it $\text{R}$, on side $\text{XZ}$.\r \n" ); document.write( "\n" ); document.write( "* From external point $\mathbf{X}$: The tangent segments are $\mathbf{XQ}$ and $\mathbf{XR}$ (assuming $\text{R}$ is the tangent point on $\text{XZ}$). \n" ); document.write( "* From external point $\mathbf{Y}$: The tangent segments are $\mathbf{YP}$ and $\mathbf{YQ}$. \n" ); document.write( "* From external point $\mathbf{Z}$: The tangent segments are $\mathbf{ZP}$ and $\mathbf{ZR}$.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "## 📏 Calculating Side Lengths\r \n" ); document.write( "\n" ); document.write( "Using the Tangent Segment Theorem and the given lengths:\r \n" ); document.write( "\n" ); document.write( "1. **Find the length of the side $\text{YZ}$**: \n" ); document.write( " * $\text{YZ}$ is given as $10$. \n" ); document.write( " * $\text{YZ} = \text{YP} + \text{PZ}$. \n" ); document.write( " * Given $\text{YP} = 6$. \n" ); document.write( " * Therefore, $\text{PZ} = \text{YZ} - \text{YP} = 10 - 6 = 4$.\r \n" ); document.write( "\n" ); document.write( "2. **Find the lengths of $\text{XQ}$ and $\text{YQ}$**: \n" ); document.write( " * Since $\text{YP}$ and $\text{YQ}$ are tangents from $\text{Y}$, we have $\mathbf{\text{YQ} = \text{YP}}$. \n" ); document.write( " $$\text{YQ} = 6$$ \n" ); document.write( " * Since $\text{XQ}$ and $\text{XR}$ (let's use $\text{XR}$ for the tangent to $\text{XZ}$) are tangents from $\text{X}$, we have $\mathbf{\text{XR} = \text{XQ}}$. \n" ); document.write( " $$\text{XR} = 4$$\r \n" ); document.write( "\n" ); document.write( "3. **Find the length of $\text{ZP}$ and $\text{ZR}$**: \n" ); document.write( " * Since $\text{ZP}$ and $\text{ZR}$ are tangents from $\text{Z}$, we have $\mathbf{\text{ZR} = \text{ZP}}$. \n" ); document.write( " * We calculated $\text{ZP} = 4$ in step 1. \n" ); document.write( " $$\text{ZR} = 4$$\r \n" ); document.write( "\n" ); document.write( "**Note:** The length $\text{XP} = 8$ and $\text{PQ} = 7$ are extraneous/conflicting if the tangency points are $\text{P}$, $\text{Q}$, and $\text{R}$ on the sides of $\triangle \text{XYZ}$. $\text{X}$, $\text{P}$, and $\text{Q}$ would not be vertices of a known figure, and $\text{XP}$ and $\text{XQ}$ are two tangent lengths from $\text{X}$, which must be equal.\r \n" ); document.write( "\n" ); document.write( "The only way the problem is solvable is if the tangency points are $\text{Q}$ on $\text{XY}$ and $\text{P}$ on $\text{YZ}$, and the third point is $\text{R}$ on $\text{XZ}$. Given that $\mathbf{\text{XQ} = 4}$ and $\mathbf{\text{XP} = 8}$, the points **$\text{P}$ and $\text{Q}$ cannot both be tangency points** to the same circle from the vertices $\text{X}$ and $\text{Y}$.\r \n" ); document.write( "\n" ); document.write( "Let's assume the labels in the diagram mean: \n" ); document.write( "* $\mathbf{XQ}$ and $\mathbf{XR}$ (on $\text{XZ}$) are tangents from $\text{X}$. $\implies \text{XQ} = \text{XR} = 4$. \n" ); document.write( "* $\mathbf{YP}$ and $\mathbf{YQ}$ are tangents from $\text{Y}$. $\implies \text{YP} = \text{YQ} = 6$. \n" ); document.write( "* $\mathbf{ZP}$ and $\mathbf{ZR}$ are tangents from $\text{Z}$. $\implies \text{ZP} = \text{ZR}$.\r \n" ); document.write( "\n" ); document.write( "The length $\mathbf{\text{XP} = 8}$ and $\mathbf{\text{PQ} = 7}$ must be disregarded as they directly contradict the Tangent Segment Theorem for the perimeter calculation, which only requires the tangent lengths from the vertices.\r \n" ); document.write( "\n" ); document.write( "## ➕ Perimeter Calculation\r \n" ); document.write( "\n" ); document.write( "The **Perimeter** $(\mathbf{Per})$ of $\triangle \text{XYZ}$ is the sum of its three side lengths: \n" ); document.write( "$$\text{Per} = \text{XY} + \text{YZ} + \text{XZ}$$\r \n" ); document.write( "\n" ); document.write( "1. **Side $\text{XY}$**: \n" ); document.write( " $$\text{XY} = \text{XQ} + \text{QY} = 4 + 6 = 10$$ \n" ); document.write( "2. **Side $\text{YZ}$**: \n" ); document.write( " $$\text{YZ} = 10 \text{ (Given)}$$ \n" ); document.write( "3. **Side $\text{XZ}$**: \n" ); document.write( " $$\text{XZ} = \text{XR} + \text{RZ}$$ \n" ); document.write( " * $\text{XR} = \text{XQ} = 4$ \n" ); document.write( " * $\text{RZ} = \text{ZP}$ \n" ); document.write( " * $\text{ZP} = \text{YZ} - \text{YP} = 10 - 6 = 4$ \n" ); document.write( " * So, $\text{XZ} = 4 + 4 = 8$\r \n" ); document.write( "\n" ); document.write( "**Total Perimeter:** \n" ); document.write( "$$\text{Per} = \text{XY} + \text{YZ} + \text{XZ} = 10 + 10 + 8 = 28$$ \n" ); document.write( " |