Emma drew lines to form triangles and octagons. Emma formed a total of 13 triangles and octagons. She drew 27 more lines for the octagons than for the triangles. How many octagons did she form?
Number of
Octagons |
Lines drawn
for the octagons |
Number of
Triangles |
Lines drawn
for the triangles |
More lines for
the octagons |
13
|
13 x 8 =
104 |
0 |
0 |
104 - 0 =
104 |
| 12 |
12 x 8 =
96 |
1 |
1 x 3 =
3 |
96 - 3 =
93 |
| 6 |
6 x 8 =
48 |
7
|
7 x 3 =
21 |
48 - 21 =
27 |
Number of lines drawn if all the shapes were octagons
= 13 x 8
= 104
Small difference
= 8 + 3
= 11
Big difference
= 104 - 27
= 77
Number of triangles that Emma drew
= 77 ÷ 11
= 7
Number of octagons that Emma drew
= 13 - 7
= 6
Answer(s): 6
