Question

16
20. Triangle PAB is formed by three tangents to circle with center O and, then angle ACB
equals
a 55°
b. 70°
c 50
d 45°​

Answer 1

Answer:

construction join OP

Now, PR=PT so PO is the angle bisector of ∠RPA

so, ∠OPR=20

0

.

alos ∠ORP=∠OTP=90

0

(radius and tangent are perpendicular to each other)

In triangle ORP,

90

0

+20

0

+∠POR=180

0

(angle sum property)

∠POR=70

0

also ∠ROP=∠POT(equal tangent subtends equal angles at the center)

similarly ∠ROB=∠BOS and ∠TOA=∠AOS

∠ROB+∠BOS+∠AOS+∠TOA=70

0

+70

0

=140

02∠BOS+2∠AOS=140

0

so, angle∠AOB=70