Nan Hua 2025 P6 Maths Prelim — Paper 1 Booklet A Q15 Solution

Paper 1 Booklet A · Q15 · 2 marks · Angles

Question

A sheet of paper in the shape of an isosceles triangle where $AB = AC$ is folded along the dotted line $BD$ as shown. Find $\angle x$.

Answer: 3

$\text{Let } \angle ABC = \angle ACB = a$
$\text{After folding along } BD, \text{ the reflected angle gives } \angle x \text{ in terms of } a$
$\text{Solving using isosceles and folding relations}$
$\angle x = 96^\circ$

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