Q2 of 186 Page 274

In the given figure, DE || BC. If DE = 5 cm, BC = 8 cm and AD = 3.5 cm then AB = ?

Given: DE ∥ BC

DE = 5 cm


BC = 8 cm


AD = 3.5 cm


To find: AB


∵ DE ∥ BC


∴ By Basic proportionality theorem, we have


………..(i)


Now, in ∆ ADE and ∆ ABC, we have


[By (i)]


∠DAE = ∠BAC [Common angle]


∴ By SAS criterion,


∆ ADE ∼ ∆ ABC




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