ABC is a right angled triangle right angled at A a circle is inscribed in it the length of two sodes...........

Quantitative Aptitude (CGL) Mensuration 2D

ABC is a right angled triangle, right angled at A. a circle is inscribed in it. the length of two sodes containing angle A is 12 cm and 5 cm. find the radius.Options:

छोटे Courses बड़े Results

Master Mensuration 2D

Prepare through Micro-courses

Try Now

Explanation:

In triangle ABC. AB = 12cm and AC = 5cm
using pythagoras theorem, BC = 13cm
Now AB AC and BC are tangents to circle.
let the point of intersection on AB be D , on BC be E, on AC be F.
Since tangents from an external point are equal, BD = BE AD = AF CE = CF .
now, AD + BD + BE + CE + CF + AF= 12 + 5 + 13
2(AD + BD + CE) = 30
AD + BD + CE = 15
AB = AD + BD
∴ 12 + CE = 15
CE = 3cm
BD = BE
BC = 13 and BE = 13 - 3
BE = 10 cm = BD
'∴ the radius is 2 cm