Let ∆ABC ~ ∆QPR and (Area of ∆ABC) : (Area of ∆PQR) = 121 : 64. If PQ = 14.4cm, PR = 12cm and AC = 18cm, then what is the length of AB?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 19.8cm
ΔABC ~ ΔQPR and (Area of ∆ABC) : (Area of ∆PQR) = 121 : 64
QP = 14.4cm, PR = 12cm and AC = 18cm
The ratio of the areas of two similar triangles is equal to the ratio of the squares of the corresponding sides.
(Area of ∆ABC)/(Area of ∆QPR) = (AB/PQ)2
(11/8)2 = (AB/14.4)2
11(14.4)/8 = AB
AB = 19.8 cm