Question

If angle a+angle b=75°,angle b +angle c=140°, find angle b

Answer 1

angle a + angle b = 75° ---(1)

angle b + angle c = 140° ------(2)

and

angle a + angle b + angle c = 180° ----(3)

eq.3 - eq.2

angle a +angle b + angle c = 180°

- angle b + angle c = 140°

----------------------------------------------------------------------

angle a = 40 °

putting a in eq. (1)

40° + angle b = 75°

angle b = 75 - 40

angle b = 35°

hope it helps

Answer 2

The angle b is 35°.

Step-by-step explanation:

Given : If angle a+angle b=75°,angle b +angle c=140°

To find : The angle b ?

Solution :

We know that,

$\angle a+\angle b+\angle c=180^\circ$

Now substitute, $\angle a+\angle b=75^\circ$

$75+\angle c=180^\circ$

$\angle c=180-75$

$\angle c=105$

Substitute in $\angle b+\angle c=140^\circ$

$\angle b+105=140^\circ$

$\angle b=140-105$

$\angle b=35^\circ$

Therefore, the angle b is 35°.

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In triangle DEF, angle D=60° ,angle E=70° and the bisector of angle E and angle F meet at O. Find angle F and angle EOF.​

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