Question

in a triangle ABC if angle a + angle b is equal to 65 degrees and angle b + angle c is equal to 1 40 degrees then the measure of angle b is​

Answer 1

Answer:

25°

Step-by-step explanation:

a + b = 65°

b + c = 140°

since, we know sum of all the angles of triangle = 180°

a + b + c = 180

65° + c = 180° => c = 115°

so angle b = 140° - 115° = 25°

Answer 2

Answer:

Step-by-step explanation:

we know in a triangle angle(a+b+c)=180degree

given that angle(a+b)=65degree then if subtract the sum of angle a+b from the sum of a+b+c i.e if subtract 65 from 180 degree we get the alue of the angle c that is 115 degree now it is also given that b+c=140 degree here if we replace the value of c with 115 degree and take it to the other side of equal sign  tha is subtract it from  140 degree we get the alue of angle b that is

a+b=140

a+115=140

a=140-115=25

hence the value of  a=25 degree