The Total solution for NCERT class 6-12
Answer - 1 : - Triangle is a three-sided polygon that consists of three edges and three vertices. The most important property of a triangle is that the sum of the internal angles of a triangle is equal to 180 degrees.
Answer - 2 : - The sum of angles of obtuse triangle = 180°.
Answer - 3 : -
∠B = 600, ∠C = 800 (given)
As per question:
∠OBC = 600/2= 300 and
∠OCB = 800/2= 400
In triangle BOC,
∠OBC + ∠OCB + ∠BOC = 180 0
[Sumof angles of a triangle = 1800]
300 +400 + ∠BOC = 1800
∠BOC = 1100
Answer - 4 : -
Let angles of atriangles are 2x, x and 3x, where x is the smallest angle.
To find: measure of x.
As, Sum of angles of atriangle = 1800
2x + x + 3x = 1800
6x = 1800
x = 300.Answer
Answer - 5 : -
Sum of angles of atriangle = 1800
A + B + C = 1800 …(1)
B – A = C – B …(Given)
2B = C + A …(2)
(1) => 2B + B = 1800
3B =1800
Or B = 600