Question

let triangle ABC= triangle DEF and their areas be respectively 64cm2 and 121cm2. if ef=15.4 cm, find BC

Answer 1

given :-
triangle ABC ~ triangle DEF
ar ( ABC ) = 64 cm2
ar (DEF ) = 121 cm2
and EF = 15.4 cm

to find :-
BC = ?

proof :-

ABC ~ DEF ( given )
=> AB ÷ DE = BC ÷ EF
we know that ...
ar ( ABC ) ÷ ar ( DEF ) = BC^2 ÷ EF^2 ( by area of similar triangles theorem ...)
=> 64 ÷ 121 = BC^2 ÷ (15.4)^2
=> 64 × (15.4)^2 ÷ 121 = BC^2
=> BC =
$\sqrt{64 \times 237.16 \div 121}$
=> BC = 8 × 15.4 ÷ 11
=> BC = 123.2 ÷ 11
=> BC = 11.2 cm

hope this will help uh ....
nd plzz mark as brainliest ...