Question

In ∆PQR, angle Q=90° ,PQ=20cm and PQ=21cm.Find the perimeter of ∆PQR.​

Answer 1

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To find perimeter of triangle we add all sides

Perimeter= (90⁰+20⁰+21⁰)cm

= 131⁰ cm

Answer 2

Answer:

70 cm

Step-by-step explanation:

In ΔPQR(see the attached figure),

PQ = 20cm and QR = 21 cm

By Pythagoras Theorem

PR = $\sqrt{PQ^{2} + QR^{2} }$

PR = $\sqrt{20^{2} + 21^{2} }$

PR = $\sqrt{400 + 441$

PR = $\sqrt{841} = 29$

So,

Prerimeter of ΔPQR = PQ + PR + QR

                                   = 20 + 21 + 29

                                   = 70 cm

∴The perimeter of ΔPQR is 70 cm.