measure of each three angles of a triangle are :

• The FIRST angle = 40°.
• The second angle = 60°.
• The third angle = 80°.

Given :

The angles of a triangle are :-

• The first angle = 2x°.
• The second angle = 3x°.
• The third angle = 4x°.

To FIND :

• The measure of each three angles.

Solution :

We know that,

SUM of all the angles of a triangle is 180°.

That means,

First angle + Second angle + Third angle = 180°

We have,

• The first angle = 2x°.
• The second angle = 3x°.
• The third angle = 4x°.

⇒ 2x° + 3x° + 4x° = 180°

⇒ 5x° + 4x° = 180°

⇒ 9x° = 180°

⇒ x° = 180° / 9

⇒ x° = 20°

Therefore,

⇒ x° = 20°

So, the measure of each angles of a triangle :

★ The first angle = 2x° = 2 × 20° = 40°

★ The third angle = 3x° = 3 × 20° = 60°

★ The fourth angle = 4x° = 4 × 20° = 80°

Hence,

The measure of each angles are 40°, 60° and 80°.

Verification :

The sum of all the three angles of a triangle is 180°.

We have,

• The first number = 40°
• The second number = 60°
• The third number = 80°

⇒ 40° + 60° + 80° = 180°

⇒ 100° + 80° = 180°

⇒ 180° = 180°

Hence VERIFIED !