In $$\triangle$$ABC, $$\angle$$C = 90$$^\circ$$ and Q is the midpoint of BC. If AB = 10 cm and AC = $$2\sqrt{10}$$ cm, then the length of AQ is:
From right angled triangle ABC,
AC$$^2$$ +Â BC$$^2$$ =Â AB$$^2$$
$$\left(2\sqrt{10}\right)^2$$ +Â BC$$^2$$ =Â $$\left(10\right)^2$$
40 +Â BC$$^2$$ = 100
BC$$^2$$ = 60
BC =Â $$2\sqrt{15}$$ cm
Q is the midpoint of BC.
CQ = $$\frac{BC}{2}$$ =Â $$\sqrt{15}$$ cm
From right angled triangle ACQ,
AC$$^2$$ + CQ$$^2$$ = AQ$$^2$$
$$\left(2\sqrt{10}\right)^2$$ +Â $$\left(\sqrt{15}\right)^2$$ =Â AQ$$^2$$
40 + 15 =Â AQ$$^2$$
AQ$$^2$$ = 55
AQ = $$\sqrt{55}$$ cm
Hence, the correct answer is Option A
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