Question

please find this question very fast and step by step please....,...

Answer 1

Refer to the diagram attached. That is one of the properties of centroid in a Right Angled ∆.
The distance of the centroid in a Right Angled triangle from the base is (height/3) and that of centroid from the height is (base/3).(Refer to the other diagram).
So, by applying Pythagorean Theorem of ∆PQR,
we get PR = 13.
Using the above property of the centroid, in Rectangle BEOF(refer my diagram), BE=OF=1.66cm BF=OE=4cm.
Now in ∆OFB,
${OB}^{2}={OF}^{2}+{OE}^{2}$
Solving this, we get,
OB= 4.308cm