Pupils from Stradbroke Primary School sent in some well-thought out
solutions to this problem. Roni explains how they worked out how much further
(from
) the point would have to turn to finish
the same height above or below the horizontal axis: 1. A whole circle is
, half a
circle is
.
take away
and then take away
another
gives the answer of
.
2. The first
is above the x line and the third
is under
the x line so it's always
.
3. A whole circle is
, you take away
and then another
. 20 add 20 equals 40. 360 take away 40 equals
. So, Roni has concluded that there are three other points where the dot would
be the same distance from the horizontal axis as it is for
. Another
way of looking at it would be to say that the dot itself would have to be at
,
,
and
. George tells us how we can work out how far a point at any position on the
circle would have to turn to finish the same height above or below the
horizontal axis. He agrees that there will be three other solutions:
1. Double the first degree and take it away from
.
2. Add
to the your starting degree.
3. Double the starting degree and take it away from
.
Well done!