Advertisements
Advertisements
प्रश्न
Use ruler and compass only for answering this question.
Draw a circle of radius 4 cm. Mark the centre as O. Mark a point P outside the circle at a distance of 7 cm from the centre. Construct two tangents to the circle from the external point P.
Measure and write down the length of any one tangent.
Advertisements
उत्तर
Steps of Construction:
- Draw a circle with centre O and radius 4 cm using a compass.
- Mark a point P on a horizontal line such that OP = 7 cm.
- Join OP.
- Draw the perpendicular bisector of OP to obtain its midpoint, say M.
- With M as centre and radius MO, draw a circle.
- This circle will cut the given circle at two distinct points A and B.
- Join PA and PB.
- PA and PB are the required tangents from the external point P to the given circle.
Measure the length of the tangent.
Length of tangent
`sqrt(OP^2 − "radius"^2)`
= `sqrt(7^2 − 4^2)`
= `sqrt(49 − 16)`
= `sqrt(33)`
= 5.74 cm (approximately)
So, the length of one tangent is 5.74 cm.

APPEARS IN
संबंधित प्रश्न
Draw a line segment AB of length 8 cm. Taking A as centre, draw a circle of radius 4 cm and taking B as centre, draw another circle of radius 3 cm. Construct tangents to each circle from the centre of the other circle.
Draw two concentric circles of radii 3 cm and 5 cm. Construct a tangent to smaller circle from a point on the larger circle. Also measure its length.
Draw a circle of radius 5 cm. Draw two tangents to this circle so that the angle between the tangents is 45°.
The bisectors of angles A and B of a scalene triangle ABC meet at O.
- What is the point O called?
- OR and OQ are drawn perpendicular to AB and CA respectively. What is the relation between OR and OQ?
- What is the relation between angle ACO and angle BCO?
Draw a circle circumscribing a regular hexagon with side 5 cm.
Draw a circle of radius 3.5 cm. Mark a point P outside the circle at a distance of 6 cm from the centre. Construct two tangents from P to the given circle. Measure and write down the length of one tangent.
Construct a tangent to a circle of radius 4 cm form a point on the concentric circle of radius 6 cm and measure its length. Also, verify the measurement by actual calculation.
Draw a circle of radius 4 cm. From a point 6 cm away from its centre, construct a pair of tangents to the circle and measure their lengths.
Use a ruler and a pair of compasses to construct ΔABC in which BC = 4.2 cm, ∠ ABC = 60°, and AB 5 cm. Construct a circle of radius 2 cm to touch both the arms of ∠ ABC of Δ ABC.
You are given a circle with radius ‘r’ and center O. You are asked to draw a pair of tangents which are inclined at an angle of 60° with each other. Refer to the figure and select the option which would lead us to the required construction. d is the distance OE.

