Question

7. Two angles of a triangle are 100° and 55° respectively. Find the third angle.​

Answer 1

Answer:

25°

Given:

First angle=100°

Second angle=55°

To find:

3rd angle of triangle

Assumption:

Let required angle be x°

Concept:

To find the 3rd angle of ∆ by using 3 sides we have to apply angle sum property of triangle.

Solution:

First angle+ second angle+ third angle=180°

100°+55°+x=180°

x=180°-100°-55°

x=25°

Related properties:

Angle sum property

⟶ This property states that sum of all angles of a triangle is equal to 180°.

Answer 2

• Given

• Measure of two angles if triangle -
• 100° and 55°

• To find

• The third angle = ?

• Solution

Let the third angle be x.

As we know,

Sum of angles of a triangle = 180°

⇛ 100° + 55° + x = 180°

⇛ 155° + x = 180°

⇛ x = 180° - 155°

⇛ x = 25°

• The value of x is 25°

•°• Third angle = 25°

━━━━━━━━━━━

Let's verify -

Sum of angles if a triangle = 180°

⇛ 100° + 55° + 25°

⇛ 180°

Hence, verified.