A is point at a distance 26 cm from the centre O of a circle of radius 10 cm. AP and AQ are the tangents to the circle at the point of contacts P and Q. If a tangent BC is drawn at a point R lying on the minor arc PQ to intersect AP at B and AQ at C, then the perimeter of $$\triangle$$ABC is:
Given, A is point at a distance 26 cm from the centre O
Radius of the circle = 10 cm
AP and AQ are tangents to the circle at the point of contacts P and Q
$$\Rightarrow$$ AP$$\bot\ $$OP and AQ$$\bot\ $$OQ
The length of tangents to the circle from an external point are equal.
$$\Rightarrow$$Â AP = AQ .................(1)
Similarly, BP = BR and CQ = CR .......(2)
In $$\triangle$$OPA,
OP$$^2$$ + AP$$^2$$ = AO$$^2$$
$$\Rightarrow$$Â 10$$^2$$ + AP$$^2$$ = 26$$^2$$
$$\Rightarrow$$Â 100 + AP$$^2$$ = 676
$$\Rightarrow$$Â AP$$^2$$ = 576
$$\Rightarrow$$Â AP = 24 cm
Perimeter of $$\triangle$$ABC = AB + BC + AC
= AB + BR + CR + AC
= AB + BP + CQ + AC [From (2)]
= AP + AQ
= AP + AP [From (1)]
= 2AP
= 2(24)
= 48 cm
Hence, the correct answer is Option A
Create a FREE account and get: