Page 76 - NUMINO Challenge_C1

Problem solving Key Points

1 When a rectangular prism has a width of 2 cm, If you want to make
a length of 2 cm, and a height of 3 cm, what is the perimeter as
the greatest possible perimeter? great as possible,
you need to connect
3 cm the most number of
short sides together.

2 cm

2 cm

2 The area of the smallest rectangle that contains For the area of the
a net can vary depending on how you draw the rectangle to be the
net. Find the area of the rectangle that contains smallest, you need
the net of a rectangular prism with a width of 3 to connect as many
cm, a length of 2 cm, and a height of 1 cm. long sides together
as possible.

1 cm 1cm
1cm

2 cm

3 cm

The area of the
smallest rectangle that
contains a net is
10 5 50 cm2.

73Geometry