You can read the story of Sarin and the siblings making greeting cards for their mother by reading posting on **Sarin, Hairu and Fatimah make greeting cards for Mother’s Day** in Welcome page.

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 UPQ132

Sarin is using a orange paper to make a greeting card for her mother.

The following figure is not drawn to scale shown the orange paper ABCD. He folds the sheet along CE. Given that ∠ ECF = 28°, find

** **(a)** **∠DEF

(b) ∠BCF

*Solution:*

Sarin folds the paper along CE,

∠ EFC = 90^{0}

Also, ∠ FEC = ∠ DEC

∠ DCE = ∠ ECF

∠ FEC = 180^{0} – 90^{0} – 28^{0} = 62^{0}

∠ DEF = 2 × ∠ FEC = 2 × 62^{0} = 124^{0}

∠ BCF = 90^{0} – 2 × 28^{0} = 34^{0}