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Standard IX

Mathematics

Triangle Inequality

In a Δ A B C,...

Question

In a ∆ABC, D and E are the mid-points of AB and AC respectively and DE = 5.6 cm. Find the length of BC.

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Solution

In ∆ABC, D and E are the midpoints of AB and AC, respectively.
By mid point theorem, DE = $\frac{1}{2}$ (BC)
∴ BC = 2 ⨯ DE
⇒ BC = 2 ⨯ 5.6 = 11.2 cm (DE = 5.6 cm)
Hence, BC = 11.2 cm

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In a ∆ABC, D and E are the mid-points of AB and AC respectively and DE = 5.6 cm. Find the length of BC.

In ∆ABC, D and E are the midpoints of AB and AC, respectively. By mid point theorem, DE = 12 (BC) ∴ BC = 2 ⨯ DE ⇒ BC = 2 ​⨯ 5.6 = 11.2 cm (DE = 5.6 cm) Hence, BC = 11.2 cm

In ∆ABC, D and E are the midpoints of AB and AC, respectively.
By mid point theorem, DE = $\frac{1}{2}$ (BC)
∴ BC = 2 ⨯ DE
⇒ BC = 2 ⨯ 5.6 = 11.2 cm (DE = 5.6 cm)
Hence, BC = 11.2 cm