Consider the truss shown in $($Figure $1).$ Assume the

members are pin connected at their end points. Take

$A=200m{m}^2$ and $E=200$GPa for each member.

Part B

Determine the vertical displacement of joint $C$ measured downward. Use Castigliano's theorem.

Express your answer to three significant figures and include the appropriate units. Enter positive

value if the displacement is downward and negative value if the displacement is upward.