Chapter 6 – Triangles

In Fig. 6.59, ABC is a triangle in which ∠ ABC < 90° and AD ⊥ BC. Prove that AC^2 = AB^2 + BC^2 – 2 BC . BD. ABC is a triangle in which ∠ ABC < 90° and AD ⊥ BC. Prove that AC^2 = AB^2 + BC^2 – 2 BC . BD. [...]

In Fig. 6.58, ABC is a triangle in which ∠ ABC > 90° and AD ⊥ CB produced. Prove that AC^2 = AB^2 + BC^2 + 2 BC . BD. ABC is a triangle in which ∠ ABC > 90° and AD ⊥ CB produced. Prove that AC^2 = AB^2 + BC^2 + 2 BC [...]

In fig. 6.57, D is a point on hypotenuse AC of triangle ABC, such that BD perpendicular AC, DM perpendicular BC and DN perpendicular AB. Prove that: (i) DM^2 =DN.MC (ii) DN^2 = DM.AN. D is a point on hypotenuse AC of triangle ABC DM perpendicular BC and DN perpendicular AB. Prove that: (i) DM^2 [...]

In Fig. 6.56, PS is the bisector of ∠ QPR of Δ PQR. Prove that ��/�� = ��/�� In Fig. 6.56 PS is the bisector of ∠ QPR of Δ PQR. Prove that ��/�� = ��/�� October 5, 2020 Category: Chapter 6 - Triangles , Maths , NCERT Class 10 ,

Tick the correct answer and justify: In ΔABC, AB = 6 root3^cm, AC = 12 cm and BC = 6 cm. The angle B is: AB = 6 root3^cm AC = 12 cm and BC = 6 cm. The angle B is: Tick the correct answer and justify: In ΔABC October 5, 2020 Category: Chapter [...]

In an equilateral triangle , prove that three times the square of one side is equal to four time the square of one of its altitudes. In an equilateral triangle prove that three times the square of one side is equal to four time the square of one of its altitudes. October 5, 2020 Category: [...]

In an equilateral triangle ABC,D is a point on side BC such that BD = 3/1 BC. Prove that 9 AD^2 = 7AB^2. D is a point on side BC such that BD = 3/1 BC. Prove that 9 AD^2 = 7AB^2. In an equilateral triangle ABC October 5, 2020 Category: Chapter 6 - Triangles [...]

The perpendicular from A on side BC of a ΔABC intersect BC at D such that DB = 3CD. Prove that 2AB^2 = 2AC^2 + BC^2. The perpendicular from A on side BC of a ΔABC intersect BC at D such that DB = 3CD. Prove that 2AB^2 = 2AC^2 + BC^2. October 5, 2020 [...]

D and E are points on the sides CA and CB respectively of a triangle ABC right angled at C. Prove that : AE^2 + BD^2 = AB^2 + DE^2 D and E are points on the sides CA and CB respectively of a triangle ABC right angled at C. Prove that : AE^2 + [...]

Two poles of height 6m and 11m stands on a plane ground, if the distance between their feet is 12m. Find the distance between their tops. if the distance between their feet is 12m. Find the distance between their tops. Two poles of height 6m and 11m stands on a plane ground October 5, 2020 [...]