Page 155 - NUMINO Challenge_B2
P. 155
Answer
Key
8 Tessellation p.68~p.69 Problem solving
Example 6 180 , 6, 180 , 6, 1080 1 A decagon can be divided into eight triangles,
1080 , 1080 , 8, 135
therefore the sum of the interior angles is
Example 60 , 6 90 , 4 108 , 4 180 8 1440 . There are ten interior angles in
120 , 3 135 a regular decagon; therefore, the measure of
each angle is 1440 10 144 .
Type 8-1 Finding the Measure of Angles p.70~p.71
2 A hexagon can be divided into four triangles;
1 The pentagon can be divided
into three triangles. Therefore, therefore, the sum of the measure of interior
the sum of the interior angles angles is 180 4 720 and the measure of one
is 180 3 540 . interior angle of a regular hexagon is
720 6 120 . Also, the measure of each angle
2 In a pentagon, the sum of the interior angles is of a regular square is 90 . Therefore, the
540°. Since the interior angles of a regular measure of angle is 360 120 90 150 .
pentagon measure the same, the measure of
each angle is 540 5 108 . Type 8-2 Placing Tiles p.72~p.73
3 The hexagon can be divided 1 The measure of angle DCH and angle CDH is
into four triangles. Therefore, 180 95 85 ; therefore, the measure of angle
the sum of the interior angles is AHB is 180 85 85 10 .
180 4 720 .
2 The sum of the angles at point H is 360 .
4 The sum of the interior angles of a hexagon is Therefore, there are 360 10 36 angles.
720 . Since the interior angles of a regular
hexagon measure the same, the measure of 3 The number of triangles is equal to the number
each angle is 720 6 120 . of trapezoids. Therefore, you need 36 trapezoids.
5 The measure of angle is equal to 360 the 4 When you stretch the two sides of the trapezoid
measures of interior angles in a regular that are not parallel to each other to make a
pentagon and hexagon. Therefore, the measure triangle, the measure of the vertex is
of angle is 360 108 120 132 . 180 80 80 20 . Therefore, you need
360 20 =18 tiles.
NUMINO Challenge B2
Key
8 Tessellation p.68~p.69 Problem solving
Example 6 180 , 6, 180 , 6, 1080 1 A decagon can be divided into eight triangles,
1080 , 1080 , 8, 135
therefore the sum of the interior angles is
Example 60 , 6 90 , 4 108 , 4 180 8 1440 . There are ten interior angles in
120 , 3 135 a regular decagon; therefore, the measure of
each angle is 1440 10 144 .
Type 8-1 Finding the Measure of Angles p.70~p.71
2 A hexagon can be divided into four triangles;
1 The pentagon can be divided
into three triangles. Therefore, therefore, the sum of the measure of interior
the sum of the interior angles angles is 180 4 720 and the measure of one
is 180 3 540 . interior angle of a regular hexagon is
720 6 120 . Also, the measure of each angle
2 In a pentagon, the sum of the interior angles is of a regular square is 90 . Therefore, the
540°. Since the interior angles of a regular measure of angle is 360 120 90 150 .
pentagon measure the same, the measure of
each angle is 540 5 108 . Type 8-2 Placing Tiles p.72~p.73
3 The hexagon can be divided 1 The measure of angle DCH and angle CDH is
into four triangles. Therefore, 180 95 85 ; therefore, the measure of angle
the sum of the interior angles is AHB is 180 85 85 10 .
180 4 720 .
2 The sum of the angles at point H is 360 .
4 The sum of the interior angles of a hexagon is Therefore, there are 360 10 36 angles.
720 . Since the interior angles of a regular
hexagon measure the same, the measure of 3 The number of triangles is equal to the number
each angle is 720 6 120 . of trapezoids. Therefore, you need 36 trapezoids.
5 The measure of angle is equal to 360 the 4 When you stretch the two sides of the trapezoid
measures of interior angles in a regular that are not parallel to each other to make a
pentagon and hexagon. Therefore, the measure triangle, the measure of the vertex is
of angle is 360 108 120 132 . 180 80 80 20 . Therefore, you need
360 20 =18 tiles.
NUMINO Challenge B2
