Question

In the given figure, PA and PB are tangents to the circle with centre O such that angle APB=50 find angle OAB

Answer 1

Answer:

Step-by-step explanation:Since OA is perpendicular to PA and also, OB is perpendicular to PB

∠APB + ∠AOB = 180°

50°+ ∠AOB = 180°

∠AOB = 180° –  50° = 130°

In △AOB,

OA = OB = radii of same circle

∠OAB = ∠OBA = x ( say )

Again, ∠OAB + ∠OBA + ∠AOB = 180°

x +x + 130° = 180°

2x = 180° –  130° = 50°

X = 25°

Hence, ∠OAB =25°

Answer 2

Answer:

1

Step-by-step explanation:

tan 45°=1                 tan(90-A)=cotA

tanA.cotA=1

tan1° x tan2° x tan3° x... x   tan45° ...  x tan(90-3)° x tan(90-2)° x tan(90-1)°

tan1° x tan2° x tan3° x...  1  x ... cot3° x cot2° x cot1°

tan1°.cot1  x  tan2°.cot2° x tan3°.cot3° ...

1x1x1

=1 =ans