Question

unit cubes and three - dimensional figures. count the number of cubes used to build each three - dimensional figure. 1 2 3 4 5 6

Explanation:

Step1: Analyze Figure 1

Count rows and columns. There are 6 rows and 4 columns, so $6\times4 = 24$ unit - cubes.

Step2: Analyze Figure 2

There are 5 rows and 5 columns, so $5\times5=25$ unit - cubes.

Step3: Analyze Figure 3

There are 3 layers, with each layer having $3\times3 = 9$ unit - cubes. So $3\times9 = 27$ unit - cubes.

Step4: Analyze Figure 4

Count visible and hidden cubes. There are 6 cubes in the bottom layer and 3 cubes in the top layer, so $6 + 3=9$ unit - cubes.

Step5: Analyze Figure 5

There are 4 cubes in the bottom layer, 4 cubes in the middle layer, and 2 cubes in the top layer. So $4 + 4+2 = 10$ unit - cubes.

Step6: Analyze Figure 6

There are 4 cubes in the bottom layer and 1 cube on top, so $4 + 1=5$ unit - cubes.

Answer:

1. 24 unit - cubes
2. 25 unit - cubes
3. 27 unit - cubes
4. 9 unit - cubes
5. 10 unit - cubes
6. 5 unit - cubes