Question

the perimeters of two similar triangles are respectively 18cm and 12cm. if pq=5cm then find ab​

Answer 1

Answer:

$given = perimeter \: = 18 \: and \: 12 \\ \\ \\ = \frac{perimeter \: of \: abc}{perimeter \: of \: pqr} = \frac{ab}{pq} \\ = \frac{18}{12} = \frac{ab}{5} \\ = 12ab = 18 \times 5 = 90 \\ 12ab = 90 \\ = ab = \frac{90}{12} \\ ab \: = 7.5 \\ \\ \\ hope \: its \: helpful \: \\ thnku \\ dhruvshi23$

Answer 2

Answer:

Since the ratio of the corresponding sides of similar triangles is same as the ratio of their perimeters.

∴   △ABC∼△PQR

⇒    

PQ

AB

​  

=  

QR

BC

​  

=  

PR

AC

​  

=  

24

36

​  

 

⇒    

PQ

AB

​  

=  

24

36

​  

 

⇒    

10

AB

​  

=  

24

36

​  

 

⇒   AB=  

24

36×10

​  

cm=15cm