Q. 14

# If each angle of a triangle is greater than the sum of the other two, show that the triangle is obtuse angled.

Proof

Let ABC be a triangle,

Now,

> +___________________ (i)

> +___________________ (ii)

> +___________________ (iii)

2 > ++ [From equation (i)]

2 > 180° [Sum of angles of triangle]

> 90° ________________ (a)

Similarly,

> 90°__________________ (b)

> 90°__________________ (c)

From equation (a), (b) and (c), each angle is less than 90°

Therefore triangle is an acute angled Proved.

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Quiz | Lines and Angles40 mins
Quiz | Lines and Angles43 mins
Lines and Angles45 mins
Quiz | Lines and Angles45 mins
NCERT | Angle Sum Property44 mins
Smart Revision | All Types of Angles31 mins
Bonus Questions on Lines and Angles42 mins
NCERT | Intersecting and Non Intersecting lines)41 mins
NCERT | Discussion on Lines And Angles45 mins
NCERT | Lines and Angles Part - 142 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
view all courses