Question : $\triangle$ ABC is a right-angled triangle with AB = 6 cm, BC = 8 cm. O is the incentre of the triangle. The radius of the in-circle is:
Option 1: 3 cm
Option 2: 4 cm
Option 3: 2 cm
Option 4: 5 cm
Correct Answer: 2 cm
Solution : AB = 6 cm, BC = 8 cm By Pythagoras theorem, $AC^2=AB^2+BC^2$ $AC = \sqrt{6^2+8^2}$ = $\sqrt{36+64}$ = $\sqrt{100}$ = $10$ cm $OP = OQ = OR = r$ Since tangents drawn from a point to the circle are equal, $RB = BP = r$ $PA = AQ = 6-r$ $RC = CQ = 8-r$ $AC = AQ + QC$ $10 = 6-r + 8-r$ ⇒ $2r = 14 – 10 = 4$ ⇒ $r = 2$ cm Hence, the correct answer is 2 cm.
Result | Eligibility | Application | Selection Process | Cutoff | Admit Card | Preparation Tips
Question : ABC is a right-angled triangle with AB = 6 cm and BC = 8 cm. A circle with centre O has been inscribed inside $\triangle ABC$. The radius of the circle is:
Question : In the given figure, point O is the centre of a circle of radius 13 cm and AB is a chord perpendicular to OD. If CD = 8 cm, what is the length (in cm) of AB?
9 Views
Question : Directions: Select the figure that will come next in the following figure series.
Question : Directions: Select the option figure in which the given figure is embedded (Rotation is NOT allowed).
Question : Directions: Select the correct mirror image of the given figure when the mirror is placed at MN as shown.
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile