Look at the following figure if \[\mathbf{b}=\mathbf{7}{{\mathbf{0}}^{{}^\circ }},\text{ }\mathbf{c}=\mathbf{11}{{\mathbf{0}}^{{}^\circ }},\mathbf{d}=\mathbf{7}{{\mathbf{0}}^{{}^\circ }}\]then find the value of a.

• A. \[{{125}^{{}^\circ }}\]                       
• B. \[{{135}^{{}^\circ }}\]         
• C. \[{{155}^{{}^\circ }}\]                       
• D. \[{{110}^{{}^\circ }}\]
• E. None of these