The areas of two similar triangles are 169 cm2 and 121 cm2 respectively. If the longest side of the larger triangle is 26 cm, what is the length of the longest side of the smaller triangle?


Given ΔABC ~ ΔPQR, ar (ΔABC): ar (ΔPQR) = 169: 121 and BC = 26 cm


We know that the ratio of areas of two similar triangles is equal to the square of the ratio of their corresponding sides.





QR2 = 4 (121)


QR2 = 484


QR = 22


The length of QR is 22 cm.


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