Question 90

In a triangle PQR, ∠Q = 90°. If PQ = 12 cm and QR = 5 cm, then what is the radius (in cm) of the circumcircle of the triangle?

Solution

Given : ∠Q = 90°, PQ = 12 cm and QR = 5 cm

To find : CIrcumradius = ?

Solution : In right angled $$\triangle$$ PQR

=> $$(PR)^2=(PQ)^2+(QR)^2$$

=> $$(PR)^2=(12)^2+(5)^2$$

=> $$(PR)^2=144+25=169$$

=> $$PR=\sqrt{169}=13$$ cm

In a right angled triangle, the circumcentre lies at the mid point of hypoenuse.

=> Circumradius = $$\frac{PR}{2}=\frac{13}{2}=6.5$$ cm

=> Ans - (C)

Share on Whatsapp Share on Whatsapp

Create a FREE account and get: