A triangle has sides A, B, and C. The angle between sides A and B is (pi)/4. If side C has a length of 1 and the angle between sides B and C is ( 3 pi)/8, what are the lengths of sides A and B?

1 Answer
Jun 4, 2018

Length of sides A and B are 1.31 unit each.

Explanation:

Angle between sides A and B is /_c= pi/4=180/4=45^0

Angle between sides B and C is /_a= (3pi)/8=540/8=67.5^0

Angle between sides C and A is

/_b= 180-(45+67.5)=67.5^0 . This is an isosceles triangle.

The sine rule states if A, B and C are the lengths of the sides

and opposite angles are a, b and c in a triangle, then:

A/sinA = B/sinb=C/sinc ; C=1 :. B/sin b=C/sin c or

B/sin 67.5=1/sin 45 or B= 1* (sin 67.5/sin 45) ~~ 1.31 (2dp)

Similarly A/sina=C/sinc or

A/sin 67.5=1/sin 45 or A= 1* (sin67.5/sin 45) ~~ 1.31 (2dp)

Length of sides A and B are 1.31 unit each [Ans]