Since A, B, C and D lie on the same circle, ABCD is a cyclic quadrilateral. In a cyclic quadrilateral, the sum of two opposite angles is 180°. Here, ∠D = 100° and ∠B = x. Therefore, x + 100° = 180° x = 180° - 100° x = 80° Hence, the value of x is 80°. For more NCERT Solutions for Class 9 MathRead more
Since A, B, C and D lie on the same circle, ABCD is a cyclic quadrilateral. In a cyclic quadrilateral, the sum of two opposite angles is 180°.
Here, ∠D = 100° and ∠B = x.
Therefore,
x + 100° = 180°
x = 180° – 100°
x = 80°
Hence, the value of x is 80°.
For more NCERT Solutions for Class 9 Maths Ganita Manjari Chapter 5 I’m Up and Down and Round and Round (2026-27):
Let the perpendicular distance from the centre to the chord be 5 cm and the radius be 13 cm. The perpendicular from the centre to a chord bisects the chord. Thus, we get a right triangle with hypotenuse 13 cm and one side 5 cm. Half chord = √(13² - 5²) = √144 = 12 cm Therefore, length of the chord =Read more
Let the perpendicular distance from the centre to the chord be 5 cm and the radius be 13 cm. The perpendicular from the centre to a chord bisects the chord. Thus, we get a right triangle with hypotenuse 13 cm and one side 5 cm.
Half chord = √(13² – 5²) = √144 = 12 cm
Therefore, length of the chord = 2 × 12 = 24 cm.
For more NCERT Solutions for Class 9 Maths Ganita Manjari Chapter 5 I’m Up and Down and Round and Round (2026-27):
The constructed triangle is an acute-angled triangle. In such triangles, the perpendicular bisectors of all three sides intersect at a point inside the triangle. This point is called the circumcentre. A circle drawn with this point as the centre passes through all three vertices of the triangle. HenRead more
The constructed triangle is an acute-angled triangle. In such triangles, the perpendicular bisectors of all three sides intersect at a point inside the triangle. This point is called the circumcentre. A circle drawn with this point as the centre passes through all three vertices of the triangle. Hence, the circumcentre of the circumcircle lies inside the triangle.
For more NCERT Solutions for Class 9 Maths Ganita Manjari Chapter 5 I’m Up and Down and Round and Round (2026-27):
The given construction forms an obtuse-angled triangle. In an obtuse-angled triangle, the perpendicular bisectors of the sides intersect at a point outside the triangle. This point is called the circumcentre. A circle drawn with this point as the centre passes through all three vertices of the trianRead more
The given construction forms an obtuse-angled triangle. In an obtuse-angled triangle, the perpendicular bisectors of the sides intersect at a point outside the triangle. This point is called the circumcentre. A circle drawn with this point as the centre passes through all three vertices of the triangle. Hence, the circumcentre lies outside the triangle.
For more NCERT Solutions for Class 9 Maths Ganita Manjari Chapter 5 I’m Up and Down and Round and Round (2026-27):
The circumcentre is the point where the perpendicular bisectors of the triangle meet. It is equally distant from all three vertices. Therefore, the lengths of OA, OB and OC are equal. When measured with a ruler, the three distances should be the same. Any slight variation is usually caused by smallRead more
The circumcentre is the point where the perpendicular bisectors of the triangle meet. It is equally distant from all three vertices. Therefore, the lengths of OA, OB and OC are equal. When measured with a ruler, the three distances should be the same. Any slight variation is usually caused by small construction or measurement errors.
For more NCERT Solutions for Class 9 Maths Ganita Manjari Chapter 5 I’m Up and Down and Round and Round (2026-27):
Find x in Fig. 5.26.
Since A, B, C and D lie on the same circle, ABCD is a cyclic quadrilateral. In a cyclic quadrilateral, the sum of two opposite angles is 180°. Here, ∠D = 100° and ∠B = x. Therefore, x + 100° = 180° x = 180° - 100° x = 80° Hence, the value of x is 80°. For more NCERT Solutions for Class 9 MathRead more
Since A, B, C and D lie on the same circle, ABCD is a cyclic quadrilateral. In a cyclic quadrilateral, the sum of two opposite angles is 180°.
Here, ∠D = 100° and ∠B = x.
Therefore,
x + 100° = 180°
x = 180° – 100°
x = 80°
Hence, the value of x is 80°.
For more NCERT Solutions for Class 9 Maths Ganita Manjari Chapter 5 I’m Up and Down and Round and Round (2026-27):
https://www.tiwariacademy.com/ncert-solutions/class-9/maths/ganita-manjari-chapter-5/
See lessIn a circle, a chord is 5 cm away from the centre. If the radius of the circle is 13 cm, what is the length of the chord?
Let the perpendicular distance from the centre to the chord be 5 cm and the radius be 13 cm. The perpendicular from the centre to a chord bisects the chord. Thus, we get a right triangle with hypotenuse 13 cm and one side 5 cm. Half chord = √(13² - 5²) = √144 = 12 cm Therefore, length of the chord =Read more
Let the perpendicular distance from the centre to the chord be 5 cm and the radius be 13 cm. The perpendicular from the centre to a chord bisects the chord. Thus, we get a right triangle with hypotenuse 13 cm and one side 5 cm.
Half chord = √(13² – 5²) = √144 = 12 cm
Therefore, length of the chord = 2 × 12 = 24 cm.
For more NCERT Solutions for Class 9 Maths Ganita Manjari Chapter 5 I’m Up and Down and Round and Round (2026-27):
https://www.tiwariacademy.com/ncert-solutions/class-9/maths/ganita-manjari-chapter-5/
See lessDraw ΔABC with AB = 5 cm, ∠A = 70° and ∠B = 60°. Draw the circumcircle of ΔABC. Is the centre inside or outside the triangle?
The constructed triangle is an acute-angled triangle. In such triangles, the perpendicular bisectors of all three sides intersect at a point inside the triangle. This point is called the circumcentre. A circle drawn with this point as the centre passes through all three vertices of the triangle. HenRead more
The constructed triangle is an acute-angled triangle. In such triangles, the perpendicular bisectors of all three sides intersect at a point inside the triangle. This point is called the circumcentre. A circle drawn with this point as the centre passes through all three vertices of the triangle. Hence, the circumcentre of the circumcircle lies inside the triangle.
For more NCERT Solutions for Class 9 Maths Ganita Manjari Chapter 5 I’m Up and Down and Round and Round (2026-27):
https://www.tiwariacademy.com/ncert-solutions/class-9/maths/ganita-manjari-chapter-5/
See lessDraw ΔABC with AB = 5 cm, ∠A = 100°, AC = 4 cm. Draw the circumcircle of ΔABC. Is the centre inside or outside the triangle?
The given construction forms an obtuse-angled triangle. In an obtuse-angled triangle, the perpendicular bisectors of the sides intersect at a point outside the triangle. This point is called the circumcentre. A circle drawn with this point as the centre passes through all three vertices of the trianRead more
The given construction forms an obtuse-angled triangle. In an obtuse-angled triangle, the perpendicular bisectors of the sides intersect at a point outside the triangle. This point is called the circumcentre. A circle drawn with this point as the centre passes through all three vertices of the triangle. Hence, the circumcentre lies outside the triangle.
For more NCERT Solutions for Class 9 Maths Ganita Manjari Chapter 5 I’m Up and Down and Round and Round (2026-27):
https://www.tiwariacademy.com/ncert-solutions/class-9/maths/ganita-manjari-chapter-5/
See lessDraw ΔABC, with AB = 6 cm, BC = 7 cm and CA = 7 cm. Draw the circumcircle of ΔABC. Let the circumcentre be O. Measure OA, OB, OC.
The circumcentre is the point where the perpendicular bisectors of the triangle meet. It is equally distant from all three vertices. Therefore, the lengths of OA, OB and OC are equal. When measured with a ruler, the three distances should be the same. Any slight variation is usually caused by smallRead more
The circumcentre is the point where the perpendicular bisectors of the triangle meet. It is equally distant from all three vertices. Therefore, the lengths of OA, OB and OC are equal. When measured with a ruler, the three distances should be the same. Any slight variation is usually caused by small construction or measurement errors.
For more NCERT Solutions for Class 9 Maths Ganita Manjari Chapter 5 I’m Up and Down and Round and Round (2026-27):
https://www.tiwariacademy.com/ncert-solutions/class-9/maths/ganita-manjari-chapter-5/
See less