# Sarin learns Shapes and Solids in school part 29 (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 the skills to deal with Math Modeling, Problem Sum from Lower Primary School to Upper Primary School level after reading the blog postings. This posting is an upper 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 UPQ264

In the figure below, ABD is an equilateral triangle, BCD is an isosceles triangle and BEDF is a rectangle. ∠BCD = 55°, ∠FDC = 20° and BD = CD. Find ∠ABE.

Solution:

BCD is an isosceles triangle and BD = CD

∠ BDC = 1800 – 2 × 550 = 700

∠ BDF = 700 – 200 = 500

BEDF is a rectangle,

∠ EBD = ∠ BDF = 500

ABD is an equilateral triangle

∠ ABD = 600

∠ ABE = 600 – 500 = 100