Question

If Ā= B + C and the magnitudes A, B and
C are 5, 4 and 3 units, the angle between
A and C is-
​

Answer 1

letA=5x

B=4x

C=3x

A+B+C=180(BY ASP OF TRAINGLE)

5x+4x+3x=180

12x. =180

x. =180/12

=15

x=15,so

A=5x=5into15= 75

B=4x=4into15=60

C=3x=3into15= 45

Now we want to find the angle between

A and C

ATQ(According to question)

A=B+C

75=B+45

B=75-45

B=30