Read posting **Sarin learns Lines and Angles (Math concept)** to understand the concept of lines and angles. Read also posting **Sarin learns Shapes and Solids in school (Math Concept)** to know about shapes.

Upper primary school mathematics question UPQ89

In the figure below, not drawn to scale, ABCD is a parallelogram. AB // EF. Find angle ∠ *x*.

*Solution:*

ABCD is a parallelogram and AB//EF,

∠ EFC = ∠ ABF = 180^{0} – 110^{0} = 70^{0 }

∠ *x* = 70^{0} + 30^{0} = 100^{0 }

or,

ABCD is a parallelogram,

∠ BCD = ∠ DAB = 110^{0}

Hence, ∠ GCD = 110^{0} – 30^{0} = 80^{0}

EF//DC and GC is a straight line,

∠ *x* = 180^{0} – 80^{0} = 100^{0}