Math worksheet for Lesson 20, featuring activities on coloring shapes, selecting numbers, and identifying sides and angles of triangles and squares.

Problem Analysis and Solution:

The provided image is an assessment worksheet from "Math 1," Lesson 20. Let's solve each part step by step.

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#### Part 1: Coloring Shapes
The task is to color the shapes according to specific instructions:
1. Color the second shape red.
2. Color the last shape yellow.
3. Color the third shape blue.
4. Color the first shape green.

The shapes are:
- First shape: Triangle
- Second shape: Square
- Third shape: Circle
- Last shape: Hexagon

Solution:
- First shape (Triangle): Green
- Second shape (Square): Red
- Third shape (Circle): Blue
- Last shape (Hexagon): Yellow

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#### Part 2: Choosing and Writing Numbers
The task is to:
1. Choose three numbers between 0 and 9.
2. Write these numbers on the lines.
3. Color the trains (not specified in the problem, so we'll assume this means marking or highlighting the chosen numbers).
4. Circle the smallest number.

Solution:
Let's choose the numbers: 3, 7, 2.

- Write the numbers on the lines:
- Line 1: 3
- Line 2: 7
- Line 3: 2

- The smallest number among 3, 7, and 2 is 2.
- Circle the number 2.

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#### Part 3: Tracing Sides and Angles
The task involves tracing sides and angles of geometric shapes and answering questions about them:
1. Trace each side of the triangle with a different color crayon.
2. Answer: How many sides does a triangle have?
3. Circle each angle of the square with a different color crayon.
4. Answer: How many angles does a square have?

Solution:
- Triangle:
- A triangle has 3 sides.
- Trace each side with a different color crayon (e.g., red, blue, green).
- Answer: 3

- Square:
- A square has 4 angles.
- Circle each angle with a different color crayon (e.g., yellow, orange, purple, pink).
- Answer: 4

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Final Answers:

1. Coloring Shapes:
- Triangle: Green
- Square: Red
- Circle: Blue
- Hexagon: Yellow

2. Choosing and Writing Numbers:
- Chosen numbers: 3, 7, 2
- Smallest number: 2 (circled)

3. Tracing Sides and Angles:
- Triangle sides: 3
- Square angles: 4

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Boxed Final Answer:

\[
\boxed{
\text{1. Triangle: Green, Square: Red, Circle: Blue, Hexagon: Yellow} \\
\text{2. Chosen numbers: 3, 7, 2; Smallest number: 2} \\
\text{3. Triangle sides: 3, Square angles: 4}
}
\]