Question

the area of two similar triangle ABC and D E F are 36 CM square and 81 cm square respectively if f is equal to 6.9 cm find BC

Answer 1

Area of two similar triangles ABC and DEF are 36 cm² and 81 cm².


So, their ratio

= 36/81

= 4/9


The ratio of area of similar triangles, is the square of the ratio of their corresponding sides. Hence, ratio of corresponding sides =
$\sqrt{ \frac{4}{9} } \\ \\ = \frac{2}{3}$

Now, EF = 6.9 cm

EF corresponds with BC, so their ratio would be 2/3

=> BC/EF = 2/3

=> BC/6.9 = 2/3

=> BC = 2/3 × 6.9

=> BC = 2 × 2.3

=> BC = 4.6 cm


Answer :- 4.6 cm