Two isosceles triangles have equal vertical angles and their areas are in the ratio 36 : 25.. Find the ratio of their corresponding heights.
Given : - AB = AC, PQ = PR and <A = <P
And AD and PS are altitudes
And, Area (ΔABC)/Area of( ΔPQR) = 36/25………………..(i)
To find: AD/PS
Proof:- Since, AB = AC and PQ = PR
Then, AB/AC = 1 and PQ/PR = 1
So, AB/AC = PQ/PR
Or, AB/PQ = AC/PR……………….(ii)
In ΔABC and ΔPQR
<A = <P (Given)
AB/PQ = AC/PR (From equation ii)
Then, ΔABC ~ ΔPQR (BY AA similarity)
So, Area of ΔABC/Area of ΔPQR = AB2 /PQ2…..(iii) (By area of similar triangle)
Compare equation I and II
AB2/PQ2 = 36/25
Or, AB/PQ = 6/5
In ΔABD and ΔPQS
<B = <Q (ΔABC ~ ΔPQR)
<ADB = <PSO (Each 90°)
Then , ΔABD ~ ΔPQS (By AA similarity)
So, AB/ PQ = AD/PS
6/5 = AD/ PS (From iv)