Question : $\triangle$ PQR circumscribes a circle with centre O and radius r cm such that $\angle$ PQR = $90^{\circ}$. If PQ = 3 cm, QR = 4 cm, then the value of r is:

Option 1: 2

Option 2: 1.5

Option 3: 2.5

Option 4: 1

Question : In $\triangle$ ABC, $\angle$ BCA = $90^{\circ}$, AC = 24 cm and BC = 10 cm. What is the radius (in cm) of the circumcircle of $\triangle$ ABC?

Option 1: 12.5

Option 2: 13

Option 3: 25

Option 4: 26

Question : If AB = 5 cm, AC = 12 cm, and AB$\perp$ AC, then the radius of the circumcircle of $\triangle ABC$ is:

Option 1: 6.5 cm

Option 2: 6 cm

Option 3: 5 cm

Option 4: 7 cm

Question : The sides of $\triangle$ABC are 10 cm, 10.5 cm and 14.5 cm. What is the radius of its circumcircle?

Option 1: 5 cm

Option 2: 7.5 cm

Option 3: 5.25 cm

Option 4: 7.25 cm

Question : If $\triangle$PQR is right-angled at Q, PQ = 12 cm and $\angle$PRQ = 30°, then what is the value of QR?

Option 1: $12\sqrt{3}$

Option 2: $12\sqrt2$

Option 3: $12$

Option 4: $24$