Question
In △ ABC, D and E are the points on sides AB and AC.
respectively and DE | BC. BC = 8 cm and DE = 5 cm. If the area of △ ADE = 45 cm², then what is the area (in cm²) of △ ABC?Solution
DE װ BC DE = 5 and BC = 8 ΔADE and ΔABC are similar. => (DE/BC)2 = Δ1/Δ2 => 25/64 = Δ1/Δ2 => 25 ------ 45 => 64 ------ (45/25) × 64 = 115.2 cm2
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