Question

Q.10- If two adjacent angles of a
parallelogram are (3x-20)° and (50-x)
o. Find the value of x.​

Answer 1

Answer:

(3x-20°)+(50°-x) =180°

2x+30°=180°

2x=180°-30°

2x=50°

x=25°

(3x-20°) = 3*25°-20°

=75°-20°

=55°

(50°-x) = 50°-25•

=25•

Answer 2

• The value of x = 75°.

Given :

The two adjacent angles of a parallelogram are :

• The first angle = (3x – 20°).
• The second angle = (50° – x).

To Find :

• The value of x.

Solution :

Given,

The two adjacent angels of a parallelogram are (3x – 20°) and (50° – x).

We know that,

The measure of the two adjacent angles is supplementary angle.

Supplementary angle = 180°

That means,

The measure of the two adjacent angles is 180°

⇒ (3x – 20°) + (50° – x) = 180°

⇒ 3x – 20° + 50° – x = 180°

⇒ 3x – x + 50° – 20° = 180°

⇒ 2x + 30° = 180°

⇒ 2x = 180° – 30°

⇒ 2x = 150°

⇒ x = 150° / 2

⇒ x = 75°

Hence,

The value of x is 75°

Verification :

We know that,

The measure of the two adjacent angles is 180°

That means,

⇒ (3x – 20°) + (50° – x) = 180°

• The value of x = 75°

⇒ [ 3 (75°) – 20° ] + [ 50° – (75°) ] = 180°

⇒ [ 225° – 20° ] + [ – 25° ] = 180°

⇒ [ 205° ] + [ – 25° ] = 180°

⇒ 205° – 25° = 180°

⇒ 180° = 180°

Hence Verified !