Question

in a triangle ABC if angle A - Angle B equal 42 degree and Angle B - angle C = 21 degree then Angle B equal?​

Answer 1

Hey mate♡♡

Answer:

53°

Step-by-step explanation:

a+b+c=180°,a-b= 42-(1),b-c=21-(2)

now we add (1) and (2) and we get a-c= 63, a=c+63,c=c,b=c+21

so c+63+c+21+c=180

3c= 180-84=96

therefore c=32, b= c+21=32+21= 53°

♡♡Hope this will helpful for you♡♡

Answer 2

Angle B is equal to 53°.

Given :

Angle A - Angle B = 42°

Angle B - Angle C = 21°

To find :

Measure of Angle B

Solution :

A - B = 42° ........(i) ; B - C = 21°..........(ii)

Adding equations i and ii :

( A - B ) + ( B - C ) = 42° + 21°

=> A - B + B - C = 63°

=> A - C = 63°

Hence, A = C + 63°

Also from equation ii :

B = C + 21°

We know,

Sum of all angles of a triangle (A + B + C) = 180°

Putting the values of A , B and C :

=> C + 63° + C + 21° + C = 180°

=> 3C + 84° = 180°

=> 3C = 180° - 84°

=> C = 96° / 3

=> C = 32°

Putting the value of C in eq. ii :

B - C = 21°

=> B - 32° = 21°

=> B = 21° + 32°

=> B = 53°

Hence, Angle B is equal to 53°.

#SPJ3