Question

the areas of two similar triangles ABC and D E F are 64 CM square and 191 CM sw
qurw respectively if ef is equal to 13.2 cm find BC

Answer 1

*** As the side EF should be 13.8 cm in place of 13.2 cm

GIVEN
Similar triangles ABC & DEF
ar of triangle ABC = 64 cm^2
ar of triangle DEF = 191 cm^2
Side EF = 13.8 cm
Side BC = ?

PROPERTIES OF SIMILAR TRIANGLES
1. They are having all three angles equal
2. Their sides are in proportional

FORMULA
(Area of 1st triangle /Area of 2nd triangle)
= side^2 of 1st triangle / side^2 of 2nd triangle
SUBSITUTE
Let the side EF = X
ar ABC / ar DEF = (BC) ^2 / (EF) ^2
64 / 191 = X^2 / (13.8)^2
X = 8 cm