In figure, ABC is a triangle .DE is parallel to BC and ADDB=43Determine the ratios ADAB,DEBC
4/7,4/7
We haveADDB=43⇒DBAD=34⇒AB−ADAD=34ABAD−1=34ABAD=34+1⇒ABAD=74⇒ADAB=47Since DE∥BC∴∠ADE=∠ABC[Corresponding angles]And,∠AED=∠ACB[Corresponding angles]So,by AA−axiom of similarity,we have△ADE∼△ABC⇒ADAB=DEBC [∵ Corresponding sides of similar triangles are proportional]⇒47=DEBCDEBC=47