Question

△​MNO​ and △​PQR​ are similar. The ratio of a side of △​PQR​ to a corresponding side of △​MNO​ is 4 : 3. If ​MN ​= 12 in., ​NO​ = 18 in., ​MO​ = 24 in., find the perimeter of △​PQR​.

Answer 1

Solve for x
4      12
--- =  ---      4x=36  36/4=9  x=9 = PQ=9in
3       x
4      18
--- =  ---       4x=54    54/4=13.5  x=13.5 QR=13.5in
3       x
4      24
--- =  ---       4x=72     72/4=18  x=18   PR=18in
3       x

18+13.5+9 = 40.5
Therefore, the perimeter of ΔPQR = 40.5inches