Official papers

Official 2021 Paper 2 · Q18

Paper 2TrigonometryGeometry

A student chooses two distinct real numbers xx and yy with 0<x<y<10<x<y<1.

The student then attempts to draw a triangle ABCABC with:

AB=1sin⁡A=xsin⁡B=y.\begin{aligned}AB&=1\\\sin A&=x\\\sin B&=y.\end{aligned}

Which of the following statements is/are correct?

  • I. For some choice of xx and yy, there is exactly one triangle the student could draw.
  • II. For some choice of xx and yy, there are exactly two different triangles the student could draw.
  • III. For some choice of xx and yy, there are exactly three different triangles the student could draw.

(Note that congruent triangles are considered to be the same.)

Anone of them
BI only
CII only
DIII only
EI and II only
FI and III only
GII and III only
HI, II and III

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