Plane Geometry
- PT is a tangent to a circle with centre O and radius 6 cm. If PT is 8 cm then length of OP is
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As per the given in question , we draw a figure of circle with centre O and PT is a tangent
Given that , OT = 6 cm. , TP = 8 cm.
∠OTP = 90°
In ∆ OPT,Correct Option: A
As per the given in question , we draw a figure of circle with centre O and PT is a tangent
Given that , OT = 6 cm. , TP = 8 cm.
∠OTP = 90°
In ∆ OPT,
OP = √OT² + TP² = √6² + 8²
OP = √36 + 64 = 100 = 10 cm.
- The chord AB of a circle of centre O subtends an angle θ with the tangent at A to the circle. Then measure of ∠ABO is :
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On the basis of question we draw a figure of a circle with centre O
Tangent ⇒ CAD
OA ⊥ CD
⇒ OAD = 90° ∠BAD = θ = ∠OBACorrect Option: B
On the basis of question we draw a figure of a circle with centre O
Tangent ⇒ CAD
OA ⊥ CD
⇒ OAD = 90° ∠BAD = θ = ∠OBA
From ∆AOB ,
∴ ∠OAB = 90° – θ = ∠OBA
- O is the centre of a circle. P is an external point of it at a distance of 13 cm from O. The radius of the circle is 5 cm. Then the length of a tangent to the circle from P upto the point of contact is :
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As per the given in question , we draw a figure of circle with centre O and P is an external point of it at a distance of 13 cm from O
Givne that , OT = 5 cm.
OP = 13 cm.
From ∆PTO ,
∴ PT = √OP² - OT²Correct Option: C
As per the given in question , we draw a figure of circle with centre O and P is an external point of it at a distance of 13 cm from O
Givne that , OT = 5 cm.
OP = 13 cm.
From ∆PTO ,
∴ PT = √OP² - OT²
PT = √13² - 5²
PT = √169 - 25 = √144 = 12 cm.
- If PQ and PR be the two tangents to a circle with centre O such that ∠QPR = 120°, then ∠POQ is :
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As per the given in question , we draw a figure of circle in which PQ and PR be the two tangents
PQ = PR (Tangents from the same exterior point)
Given , ∠QPR = 120°∠OPQ = ∠OPR = 120° = 60° 2
∴ OQ ⊥ PQ (Tangent)
Correct Option: C
As per the given in question , we draw a figure of circle in which PQ and PR be the two tangents
PQ = PR (Tangents from the same exterior point)
Given , ∠QPR = 120°∠OPQ = ∠OPR = 120° = 60° 2
∴ OQ ⊥ PQ (Tangent)
From ∆OQP ,
∴ ∠OQP = 90°
∴ ∠POQ + ∠OPQ = 90°
∴ ∠POQ = 90° – 60° = 30°
- T is a point on the common tangents at P of two circles and if TA and TB are respectively the other tangents at A and B to the two circles drawn from the point T then
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According to question , we draw a figure of two circles and T is a point on the common tangents at P
We can say that tangents drawn from an external point to a circle are equal.Correct Option: B
According to question , we draw a figure of two circles and T is a point on the common tangents at P
We can say that tangents drawn from an external point to a circle are equal.
∴ TA = TP; TP = TB
∴ TA = TB