Question

If triangle ABC and triangle DEF are two similar triangles such that BC=4cm, EF=5cm and area of triangleABC=64cm² then area of triangle DEF is

Answer 1

Ar(ABC)/ar(DEF)=BC/EF. (by theorem) 

80/ar(DEF)=4/5

ar(DEF)=80*5/4

ar(DEF)=100 cm sq.

4.5

Answer 2

HERE'S YOUR ANSWER

ABC & DEF are two similar triangle

area of ABC/area of DEF = BC^2/EF^2

given area of ABC=64

therefore, 64/area of DEF = 4^2/5^2

Area of DEF=64×25/16

AREA OF DEF = 100cm^2