Question

tell the solution anyone. ​

Answer 1

Since, we know that sum of angles on straight lime is 180°.So,

3x-5+55°+x+20°=180°

= 4x+70°=180°

=4x=180°-70°

=4x=110°

=x=110°/4

x=>27.5°

Answer 2

$\green\bigstar$Answer:

$\boxed{\: x \: = \: {27.5} ^{ \circ}}$

$\blue\bigstar$ Given:

• AOB is a straight line
• $\angle$AOC = (3x - 5)°
• $\angle$COD = 55°
• $\angle$BOD = (x + 20)°

$\red\bigstar$To find:

• The value of x

$\pink\bigstar$ Solution:

$\because$AOB is a straight line,

$\therefore$ (3x - 5)° + 55° + (x + 20)° = 180°

( The sum of angles in a straight line is 180° )

$\implies$ (3x + x)° + 55° + 20° - 5° = 180°

$\implies$ 4x + 70° = 180°

$\implies$ 4x = 180° - 70°

$\implies$ 4x = 110°

$\sf \implies \: x \: = \: \cancel \frac{{110}^{ \circ}}{4}$

$\sf\implies \boxed{\: x \: = \: {27.5} ^{ \circ}}$

$\boxed{\therefore \: x \: = \: {27.5} ^{ \circ}}$

$\blue\bigstar$ Concepts Used:

• Assumption of the Unknown angle
• Sum of all angles in a straight line is 180°
• Transposition Method

$\green\bigstar$Extra - Information:

• Acute angle - An angle between 0° and 90°
• Right angle - An 90° angle
• Obtuse angle - An angle between 90° and 180°
• Straight angle - A 180° angle
• Reflex Angle - An angle between 180° and 360°
• Complete Angle - A 360° angle
• Complementary angles are a Pair of Angles whose sum is 90°
• Supplementary Angles are a pair of angles whose sum is 180°