In the following figure, a circle is inscribed in the quadrilateral ABCD.
If BC = 38 cm, QB = 27 cm, DC = 25 cm and that AD is perpendicular to DC, find the radius of the circle.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
From the figure we see that BQ = BR = 27 cm (since length of the tangent segments from an external point are equal)
As BC = 38 cm
CR = CB − BR = 38 − 27
= 11 cm
Again,
CR = CS = 11cm (length of tangent segments from an external point are equal)
Now, as DC = 25 cm
∴ DS = DC − SC
= 25 − 11
= 14 cm
Now, in quadrilateral DSOP,
∠PDS = 90° (given)
∠OSD = 90°, ∠OPD = 90° (since tangent is perpendicular to the radius through the point of contact)
DSOP is a parallelogram
OP ∥ SD and PD ∥ OS
Now, as OP = OS (radii of the same circle)
OPDS is a square. ∴ DS = OP = 14cm
∴ radius of the circle = 14 cm