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प्रश्न
Ratio of corresponding sides of two similar triangles is 4 : 7, then find the ratio of their areas = ?
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उत्तर
Let the corresponding sides of similar triangles be s1 and s2.
Let A1 and A2 be their corresponding areas.
s1 : s2 = 4 : 7 ...[Given]
∴ `(s_1)/(s_2) = 4/7` ...(i)
`(A_1)/(A_2) = (s_1^2)/(s_2^2)` ...[Theorem of areas of similar triangles]
`(A_1)/(A_2) = (s_1/s_2)^2`
`(A_1)/(A_2) = (4/7)^2` ...[From (i)]
`(A_1)/(A_2) = 16/49`
∴ Ratio of areas of similar triangles = 16 : 49
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In the figure, PQ ⊥ BC, AD ⊥ BC. To find the ratio of A(ΔPQB) and A(ΔPBC), complete the following activity.

Given: PQ ⊥ BC, AD ⊥ BC
Now, A(ΔPQB) = `1/2 xx square xx square`
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Therefore,
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