8-1. Kolya made a figure from four identical blocks as shown in the picture. What is the surface area of this figure? Express your answer in square centimeters.

![](https://cdn.mathpix.com/cropped/2024_05_06_8b3efc685c220cbeb247g-1.jpg?height=450&width=1295&top_left_y=786&top_left_x=355)
Answer: 64.

Solution. The surface area of one block is 18 cm². Out of this area, 2 cm² is "lost" at the joints with other blocks, leaving a total area of $18-2=16$ cm². Since there are 4 blocks, the answer is $4 \cdot 16=64$ cm².