How do you solve a triangle ABC given A=150 degrees, C= 20 degrees, a= 200?

1 Answer
Feb 11, 2018

the six elements of a triangle are:
Sides
a=200a=200
b=69.459b=69.459
c=136.808c=136.808
Angles
A=150A=150
B=10B=10
C=20C=20

Explanation:

Given:
Angle A=150A=150
Angle C=20C=20
Side a=200a=200
To find
Angle BB
We know that
A+B+C=180A+B+C=180
Substituting fir A and C
150+B+20=180150+B+20=180
170+B=180170+B=180
B=180-170B=180170
Solving for B
B=10B=10
Side b
b/sinB=a/sinAbsinB=asinA
b=a(sinB/sinA)b=a(sinBsinA)
Substituting for A, B and a
b=200(sin10/sin150)b=200(sin10sin150)
b=69.459b=69.459
Side c
c/sinC=a/sinAcsinC=asinA
c=a(sinC/sinA)c=a(sinCsinA)
Substituting for A, C and a
c=200(sin20/sin150)c=200(sin20sin150)
c=136.808c=136.808

Thus, the six elements of a triangle are:
Sides
a=200a=200
b=69.459b=69.459
c=136.808c=136.808
Angles
A=150A=150
B=10B=10
C=20C=20