Hi Chris Rogers,

I got a request via PM from bluefire about Q34 and Q35 from Nanyang 2007 P6 Prelim Q34 and Q35.

Could you pls help to post Q34 and Q35 and add further explanations to help bluefire? My explanations may not be enough for him to understand as you will need to mark the necessary details in the diagram itself. Thanks in advance.

Hi bluefire,

On Q34, take note of the unit shape of the tessellation. It's a irregular polygon with 9 sides. The sum of angles in a regular/irregular polygon with n sides, where n is 3 or more, is 180⁰x(n-2).

In this case with 9 sides, sum of angles = 180⁰x(9-2) = 180⁰x7 = 1260⁰

First, you have to work on Q33 (a) and (b). For Q33 (b), mark angle b and angle c. You divide 360⁰ by 6 to get 60⁰ for angle b.It's difficult to explain in words here and I will leave it to Chris. Then you have to mark 3 pairs of angle which add to 360⁰.Chris will assist on this.So, you will have:

1260⁰-360⁰-360⁰-360⁰-40⁰-60⁰ = 80⁰
Angle a = 80⁰

On Q35, let me try to explain in words while waiting for Chris to add on:

Work on figure 2,
Angle BAC = Angle BCA = 45⁰
Angle BAD = 90⁰
Angle CAD=90⁰+45⁰=135⁰

Next work on figure 3,
Angle DAC=Angle CAD=135⁰
Angle ACD = 22.5⁰ (45⁰ divided by 2)
Angle ADC= 180⁰-135⁰-22.5⁰=22.5⁰

Finally, work on figure 4,
From point A, there is a line drawn to join another point. Mark this point as I.
Angle ADI = Angle ADC = 22.5⁰
Angle GDI = Angle B = 180⁰-22.5⁰ = 157.5⁰

For Question 34, I have done it a different way by extending the tessellation as the approach you have taken, I believe, is beyond what is taught in P6 (i.e. the sum of angles in a regular/irregular polygon with n sides, where n is 3 or more, is 180⁰x(n-2)).



I'll send bluefire a message, as I know who she is

I'll have a look at question 35 this afternoon.

Thank you Chris Rogers and Perserverance.@Chris Rogers,I already understand both questions already.But I asked perserverance about Q37 also in this paper,i dont understand what support ratio mean,how to solve that question? I tried to drew the table out but in vain,it just jumble up when i preview it n also i cant scan,is different format.Pls help me!
Thanks a bunch in advance.

O Chris Rogers, I jus saw the message that Perserverance PM me,she already helped me for Q37.
Txs:)