Find the best tutors and institutes for Class 10 Tuition
Q1:
In each of the following, give also the justification of the construction:
Draw a circle of radius 6 cm. From a point 10 cm away from its centre, construct the pair of tangents to the circle and measure their lengths.
Solution :
Given: A circle with center $O$ and radius $r = 6\text{ cm}$. A point $P$ located at a distance $OP = 10\text{ cm}$ from the center $O$.
To Find: Construct a pair of tangents from point $P$ to the circle and measure their lengths.
Step 1: Construction Procedure
1. Draw a circle with center $O$ and radius $6\text{ cm}$.
2. Mark a point $P$ such that $OP = 10\text{ cm}$.
3. Draw the line segment $OP$. Find the midpoint $M$ of $OP$ by drawing the perpendicular bisector of $OP$.
4. With $M$ as the center and $MO$ as the radius, draw a circle. This circle will intersect the original circle at two points, $T_1$ and $T_2$.
5. Join $PT_1$ and $PT_2$. These are the required tangents.
Step 2: Justification
To justify that $PT_1$ and $PT_2$ are tangents, we join $OT_1$.
In $\triangle OT_1P$, $\angle OT_1P$ is an angle in a semicircle. [By Thales' Theorem, the angle subtended by a diameter at the circumference is $90^\circ$].
Therefore, $\angle OT_1P = 90^\circ$.
Since $OT_1$ is a radius of the circle, $PT_1$ must be a tangent to the circle at $T_1$. [Since a line perpendicular to the radius at the point of contact is a tangent].
Step 3: Calculation of Tangent Length
In the right-angled triangle $\triangle OT_1P$:
$OP^2 = OT_1^2 + PT_1^2$ [Using Pythagoras Theorem]
Given $OP = 10\text{ cm}$ and $OT_1 = 6\text{ cm}$ (radius).
$10^2 = 6^2 + PT_1^2$
$100 = 36 + PT_1^2$
$PT_1^2 = 100 - 36$
$PT_1^2 = 64$
$PT_1 = \sqrt{64} = 8\text{ cm}$.
Final Answer: The length of each tangent is 8 cm.
More Questions from Class 10 Mathematics Constructions EXERCISE 11.2
- Q2: In each of the following, give also the justification of the construction: Construct a tangent to a circle of radius 4 cm from a point on the concentric circle of radius 6 cm and measure its length. Also verify the measurement by actual calculation.
- Q3: In each of the following, give also the justification of the construction: Draw a circle of radius 3 cm. Take two points $P$ and $Q$ on one of its extended diameter each at a distance of 7 cm from its centre. Draw tangents to the circle from these two points $P$ and $Q$.
- Q4: In each of the following, give also the justification of the construction: Draw a pair of tangents to a circle of radius 5 cm which are inclined to each other at an angle of $60^{\circ}$.
- Q5: In each of the following, give also the justification of the construction: 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.
- Q6: In each of the following, give also the justification of the construction: Let ABC be a right triangle in which $AB = 6$ cm, $BC = 8$ cm and $\angle B = 90^{\circ}$. $BD$ is the perpendicular from $B$ on $AC$. The circle through $B$, $C$, $D$ is drawn. Construct the tangents from $A$ to this circle.
- Q7: In each of the following, give also the justification of the construction: Draw a circle with the help of a bangle. Take a point outside the circle. Construct the pair of tangents from this point to the circle.
CBSE Solutions for Class 10 Mathematics Constructions
Chapters in CBSE - Class 10 Mathematics
Top Tutors who teach Constructions
Teaching is my passion I am into teaching profession since 16 years. I like challenges with young minds.. I will make students to confident by explaining concepts, taking special care. Cent percent assurance to child growth, committed to work towards target. I used to counsel the students to succeed in their exams.
Math and physics teacher. Expert in cbse education and assessment patten. Been an cbse examiner for 5 continuous years. Aware of the curriculum of ssc, icse and cbse grade 7-10 math and physics. Tutoring since 2006 and been quite successful in giving results.
I enjoy teaching and making things easier and fun for the children. Didn't send my kids for any tuitions. Today the elder child is a CSE graduate , working for Amazon & the other is in her 3rd year MBBS !
I have been studying Maths and Science under her guidance since 8th grade. She explains every concept in a simple and clear way, making even difficult topics easy to understand. Her teaching style is patient and supportive, and she always makes sure all doubts are cleared. She focuses on strengthening basics and gives regular practice, which has really helped me improve. Because of her guidance, my confidence in both subjects has increased a lot. I am truly grateful for her dedication and support
I am a strong believer in concept-based gain of knowledge. I start from scratch while teaching the very basic concepts and take my students to a level where they have a deep understanding of the subject. Once they understand the concept, the next step is that practice a lot of questions/numerical/problem in the class itself as practice is the key to retain knowledge. I always refer to prescribed books by CBSE/ICSE board but always encourage students to refer additional 1 or 2 books based on their speed to practice. In last I provide them enough homework to practice at home and send me the doubts before the next class. Also for 10th students, we prepare right from beginning by covering the previous year questions and this approach till date have been fruitful as most of my students excel in the board exams
I was a teacher at a CBSE-affiliated school. I have six years of experience teaching on online platforms. I have been conducting Mathematics, Physics, and Chemistry classes for high school and higher secondary students for more than 20 years. I believe I can encourage and motivate students to achieve excellent academic results while inspiring them to develop good values and habits.
Sini ma'am is an excellent maths teacher. I joined her classes at exactly the right time when I needed clarity, and she explained every concept in a very simple and structured way. Her teaching style made even difficult topics easy to understand, and my confidence in maths improved a lot in a short period. She is very patient, supportive, and genuinely cares about her students’ understanding. I’m really grateful for the guidance and clarity she gave me.
Find more Tutor for Constructions in your City
- Bangalore Mathematics Tutors
- Delhi Mathematics Tutors
- Chennai Mathematics Tutors
- Gurgaon Mathematics Tutors
- Noida Mathematics Tutors
- Hyderabad Mathematics Tutors
- Mumbai Mathematics Tutors
- Chandigarh Mathematics Tutors
- Pune Mathematics Tutors
- Ghaziabad Mathematics Tutors
- Jaipur Mathematics Tutors
- Surat Mathematics Tutors
Download free CBSE - Class 10 Mathematics Constructions EXERCISE 11.2 worksheets
Download Now