Question $1(6$ marks$)$

Explain the following terms as used in flexibility method to analyse indeterminate structures.

$($a$)$ Primary structure

$($b$)$ Release system

Illustrate your explanation with diagrams

Question $2(24$ marks$)$

Use flexibility method to analyse the rigid frame shown in Figure $1$ and find the maximum

span bending moment between B and C$.$ Assume EI is constant.