Question

what will be the value of Optus angle in the following figure​

Answer 1

138 is the right answer

X=14
12x-30+3x=180
12x+3x=210
15x=210
3x=42x=14
12x-30=138

Answer 2

Answer : (B) 138°

Note:

In the question we can see that the figure makes an angle of complete 180°.

Information:

• Acute: Angle which is less than 90° but more than 0°.
• Right: Angle which is exactly 90°.
• Obtuse: Angle which is more than 90° but less than 180°.

Procedure:

$= > 3x + 12x - 30 = 180$

$= > 15x - 30 = 180$

$= > 15x = 210$

$= > x = 14$

WKT,

Obtuse Angle is more than 90° and less than 180°, So the angle more than 90° in the given figure makes an angle of 12x-30°.

Now,

$Substitute\:value\:of\:'x'$

$=>12(14) - 30$

$=>168 - 30$

$=>138°$