Question

Two angles of a triangle are 60degree

and 40degree

. Find the third angle of a

triangle.​

Answer 1

Answer:

Third angle is 80°

Step-by-step explanation:

Let the third angle be x

x+60°+40°=180°(Angle sum property of a triangle)

x+100°=180°

x=180°-100°

x=80°

Answer 2

★ Concept :-

• There are 3 types of triangles :-

1. Isosceles triangle.
2. Scalene triangle.
3. Equilateral triangle.

• Isosceles triangle :- If two sides of the triangle are equal it is called isosceles triangle.

• Scalene triangle :- If three sides of a triangle are different it is called a scalene triangle.

• Equilateral triangle :- If three sides of a triangle are equal it is called a equilateral triangle.

• The sum of three sides of the triangle is 180°

★ Required solution :-

Given:-

• First angle of the triangle = 60° (A)
• Second angle of the triangle = 40°(B)

To find:-

• Third angle of the triangle = ?

Solution:-

We know that,

• Sum of angles of the triangle = 180°

Let the third angle be x

➥ 60° + 40° + x = 180°

➥ 100° + x = 180°

➥ x = 180° - 100°

➥ x = 80°

Hence:-

• The third angle of the triangle = 80°.
• It is a scalene triangle.

Figure :-

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