In the given figure, a circle inscribed in $$\triangle$$ PQR touches its sides PQ, QR and RP at points S, T and U,respectively. If PQ = 15 cm, QR= 10 cm, and RP = 12 cm, then find the lengths of PS, QT and RU?
Given, PQ = 15 cm, QR= 10 cm, and RP = 12 cm
PS and PU are tangents to the circle from point P.
$$\Rightarrow$$Â PS = PU
Let PS = PU = x
QT and QS are tangents to the circle from point Q.
$$\Rightarrow$$Â QT = QS
Let QT = QS = y
RU and RTÂ are tangents to the circle from point R.
$$\Rightarrow$$Â RU = RT
Let RU = RT = z
PQ = 15 cm
$$\Rightarrow$$ PS + QS = 15
$$\Rightarrow$$ x + y = 15 ........(1)
Similarly,
y + z = 10 ..........(2)
z + x = 12 ..........(3)
Adding (1), (2), (3)
x + y + z = 18.5 .......(4)
From (1) and (4), z = 3.5 cm
From (2) and (4), x = 8.5 cm
From (3) and (4), y = 6.5 cm
$$\therefore\ $$PS = 8.5 cm, QT = 6.5 cm and RU = 3.5 cm
Hence, the correct answer is Option B
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