# Sarin learns Shapes and Solids in school part 28 (Math Question)

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The blog postings are about the Singapore Math. The readers can learn from the postings on Solving Singapore Primary School Mathematics. The blog presenting the Math Concept, Math Questions with solutions that teaches in Singapore Primary Schools. You or the kids can learn deal with Math Modeling, Problem Sum from Lower Primary School to Upper Primary School level. This posting is a primary school math question on Angle and Shape.

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

Upper primary school mathematics question UPQ216

In the figure, AGED is a parallelogram. ACD and DFE are triangles. Given that

∠ FGB =70°. ∠ ACD =30° and ∠ BDA =30°, find ∠ HDB.

Solution:

AGED is a parallelogram, AD//GE and FGHE is a straight line

∠ DAB = ∠ FGB = 700

ACD is a triangle

∠ HDB = 1800 – 300 – 300 – 700 = 500

Alternative solution:

AGED is a parallelogram, AG//DE and CD is a straight line

∠ HDE = ∠ GCH = 300

∠ HED = ∠ FGB = 700

∠ HDB = 1800 – 300 – 300 – 700 = 500