The assembly consists of two bars AB and CD of the same material having a modulus of ela...

The assembly consists of two bars AB and CD of the same material having a modulus of elasticity E₁ and coefficient of thermal expansion α₁, and a bar EF having a modulus of elasticity E2 and coefficient of thermal expansion α₂. All the bars have the same length L and crosssectional area A. If the rigid beam is originally horizontal at temperature T₁, determine the angle it makes with the horizontal when the temperature is increased to T₂.