Page 116 - NUMINO Challenge_C1

Basic Concepts Figures Formed by Connecting Dots

There are various ways to find the area of a figure which is formed by

connecting dots on a dotted paper.

1

1 AB
B C

A

Find the length of the Divide the figure into Subtract the areas of
base and height. separate figures and find the other parts from
the area of each separate the area of the entire
Area: 1 2 2 1 figure. Then find the sum square.
of the areas of the
separate figures. Area: 1
2
Area: A B 3 4 (A B C) 1

Example The figures below are formed by connecting dots on dotted paper.

If the distance between each dot is 1 cm, find the areas of figures

A and B.

1 cm

1 cm

A B

Class Notes

The area of figure A can be found by subtracting the areas of three
uncolored triangles , , and from the area of the entire square.

( ) (3 1 2) ( 2) ( 2) cm2

The area of figure B can be found by finding the areas of the two
triangles that have a known base and height.

( 2) ( 2) cm2

Therefore, the area of figure A is cm2 and the area of figure B is
cm2.

113Measurement