Chapter 7 – Triangles
10. Prove that sum of any two sides of a triangle is greater than twice the median with respect to the third side.
30
Jun
10. Prove that sum of any two sides of a triangle is greater than twice the median with respect to the third side. 10. Prove that sum of any two sides of a triangle is greater than twice the median with respect to the third side. June 30, 2021 Category: Chapter 7 - Triangles , [...]
9. ABC is an isosceles triangle in which AC = BC. AD and BE are respectively two altitudes to sides BC and AC. Prove that AE = BD.
30
Jun
9. ABC is an isosceles triangle in which AC = BC. AD and BE are respectively two altitudes to sides BC and AC. Prove that AE = BD. 9. ABC is an isosceles triangle in which AC = BC. AD and BE are respectively two altitudes to sides BC and AC. Prove that AE = [...]
8. ABC and DBC are two triangles on the same base BC such that A and D lie on the opposite sides of BC, AB = AC and DB = DC. Show that AD is the perpendicular bisector of BC.
30
Jun
8. ABC and DBC are two triangles on the same base BC such that A and D lie on the opposite sides of BC, AB = AC and DB = DC. Show that AD is the perpendicular bisector of BC. 8. ABC and DBC are two triangles on the same base BC such that A [...]
7. O is a point in the interior of a square ABCD such that OAB is an equilateral triangle. Show that ∆ OCD is an isosceles triangle.
30
Jun
7. O is a point in the interior of a square ABCD such that OAB is an equilateral triangle. Show that ∆ OCD is an isosceles triangle. 7. O is a point in the interior of a square ABCD such that OAB is an equilateral triangle. Show that ∆ OCD is an isosceles triangle. June [...]
6. ABC is a right triangle with AB = AC. Bisector of ∠A meets BC at D. Prove that BC = 2 AD.
30
Jun
6. ABC is a right triangle with AB = AC. Bisector of ∠A meets BC at D. Prove that BC = 2 AD. 6. ABC is a right triangle with AB = AC. Bisector of ∠A meets BC at D. Prove that BC = 2 AD. June 30, 2021 Category: Chapter 7 - Triangles , [...]
5. ABCD is a quadrilateral in which AB = BC and AD = CD. Show that BD bisects both the angles ABC and ADC.
30
Jun
5. ABCD is a quadrilateral in which AB = BC and AD = CD. Show that BD bisects both the angles ABC and ADC. 5. ABCD is a quadrilateral in which AB = BC and AD = CD. Show that BD bisects both the angles ABC and ADC. June 30, 2021 Category: Chapter 7 - [...]
4. P is a point on the bisector of ∠ABC. If the line through P, parallel to BA meet BC at Q, prove that BPQ is an isosceles triangle.
30
Jun
4. P is a point on the bisector of ∠ABC. If the line through P, parallel to BA meet BC at Q, prove that BPQ is an isosceles triangle. 4. P is a point on the bisector of ∠ABC. If the line through P parallel to BA meet BC at Q prove that BPQ is [...]
3. ABC is an isosceles triangle with AB = AC and D is a point on BC such that AD ⊥ BC (Fig. 7.13). To prove that ∠BAD = ∠CAD, a student proceeded as follows:
30
Jun
3. ABC is an isosceles triangle with AB = AC and D is a point on BC such that AD ⊥ BC (Fig. 7.13). To prove that ∠BAD = ∠CAD, a student proceeded as follows: 3. ABC is an isosceles triangle with AB = AC and D is a point on BC such that AD [...]
2. The image of an object placed at a point A before a plane mirror LM is seen at the point B by an observer at D as shown in Fig. 7.12. Prove that the image is as far behind the mirror as the object is in front of the mirror.
30
Jun
2. The image of an object placed at a point A before a plane mirror LM is seen at the point B by an observer at D as shown in Fig. 7.12. Prove that the image is as far behind the mirror as the object is in front of the mirror. 6. S is any [...]
1. Find all the angles of an equilateral triangle.
30
Jun
1. Find all the angles of an equilateral triangle. 1. Find all the angles of an equilateral triangle. June 30, 2021 Category: Chapter 7 - Triangles , Maths , NCERT Class 9 ,