Question

Consider triangle PQR, where Q is right angle, & the area of triangle s 12 unit2

. Prove that length of PR is

least when PQ = QR. Maxima minima
​

Answer 1

Step-by-step explanation:

Given that:

QP=8cm,PR=6cm and SR=3cm

(I)  In △PQR and △SPR

∠PRQ=∠SRP  (Common angle)

∠QPR=∠PSR   (Given that)

∠PQR=∠PSR   (Properties of triangle )

∴△PQR∼△SPR  (By AAA)

(II)   SPPQ=PRQR=SRPR  (Properties of similar triangles)

⇒SP8cm=3cm6cm

⇒SP=4cm and 

⇒6cmQR=3cm6cm

⇒QR=12cm

(III)ar(△SPR)ar(△PQR)=SP2PQ2=4282=4