The vertex A of ∆ABC is joined to a point D on BC. If E is the midpoint of AD, then ar(∆BEC) = ?
Given:
Here,
D is the midpoint of BC and AD is the median of ΔABC
Area (Δ ABD) = Area (Δ ADC) (∵ median divides the triangle into two triangles of equal areas)
∴ Area (Δ ABD) = Area (Δ ADC) = Area (∆ABC)
Now, consider Δ ABD
Here, BE is the median
Area (Δ ABE) = Area (Δ BED)
∴ Area (Δ ABE) = Area (Δ BED) = Area (∆ABD)
Area (Δ BED) = Area (∆ABD)
Area (Δ BED) = ×
(∵Area (Δ ABD) =
Area (∆ABC) ) –1
Area (Δ BED) = Area (∆ABC)
Similarly,
Area (Δ EDC) = Area (∆ABC) –2
Add –1 and –2
Area (Δ BED) + Area (Δ EDC) = Area (∆ABC) +
Area (∆ABC) =
Area (∆ABC)
∴ Area (Δ BEC) = Area (∆ABC)