# Decompose Angles using Pattern Blocks

Examples, solutions, and videos to help Grade 4 students learn how to decompose angles using pattern blocks.

Common Core Standards: 4.MD.7

### New York State Common Core Math Grade 4, Module 4, Lesson 9

NYS Math Module 4 Grade 4 Lesson 9 Concept Development

Problem 1: Derive the angle measures of an equilateral triangle.

Place squares around a central point. Fit them like puzzle pieces. Point to the central point. How many right angles meet at this central Point Y?

How many quarter-turns are there around the central point?

Arrange a set of green triangles around a central point. How many triangles did you fit around the central point?

NYS Math Module 4 Grade 4 Lesson 9 Homework

Sketch two different ways to compose the given angles using two or more pattern blocks. Write an addition sentence to show how you composed the given angle.

1. is a straight line.
2. ∠DEF = 90°
3. ∠GHI = 120°
4. x° = 270°
5. Micah built the following shape with his pattern blocks. Write an addition sentence for each angle indicated by an arc and solve. The first one is done for you as an example.

Try the free Mathway calculator and problem solver below to practice various math topics. Try the given examples, or type in your own problem and check your answer with the step-by-step explanations.