# Angles of the Sun -- Out Teach

## Overview

In this lesson, students will apply the use of angles to a real-world problem—finding the angle of the sun to determine the placement of solar panels. This lesson can be used to teach about angles, or to reinforce and apply understanding of angles.

# Set up / Background

Math: Students in these grades will likely have the background knowledge of different kinds of angles ( acute, obtuse, right), however if they do not, allow that academic language to be introduced during the explain portion of this lesson. Acute angles are less than 90 degrees. Right angles are 90 degrees. Obtuse angles are greater than 90 degrees.

Remind students of the outdoor learning expectations: walking not running, don't throw objects, try not to harm plants.

Science: This lesson is based in renewable energy and placement of solar panels. Renewable energy is energy collected from resources which are naturally replenished, such as sunlight, wind, rain, tides, waves, and geothermal heat. Solar panels are a structure that captures that energy and converts it for human use, most times for electricity. Students will also be observing how the sun appears in the sky. Where the sun appears the sky is due to the rotation of the Earth, not the movement of the sun. This is a common misconception with students. When answering student questions or talking about the movement, use language such as " how the sun appears to move" versus "the movement of the sun" to reinforce the concept.

# Key Vocabulary

• Angles

• Protractor

• Acute

• Obtuse

Right

# Guiding Question

In the real world, why is it important to have an understanding of measurement?

# Engage

**Ask:** What do you know about solar power? What about renewable and non-renewable energy?

Accept answers. If students do not have familiarity, briefly describe.

**Ask:** If we were asked to place solar panels on this

Discuss that people need to know the angles of the sun to solve "Real-world" problems for things like growing food and using solar power.

Explain that today they will find the angle of the sun relative to locations around the school building in order to determine placement for solar panels.

Note: If your class has never discussed solar panels or renewable energy, but has focused on growing plants and the amount of sunlight they need, this activity can be shifted with a real-world focus to the needs of certain plants.

# Explore

Ask students to explore the outdoor classroom in pairs or teams and to observe the ways that they imagine the apparent movement of the sun across the sky during the day.

Ask students to use the ground as the starting point line, sketch the current angle of the sun, and use their protractor to measure the angle. For example:

In the diagram below, "N" marks the ground and "M" marks the relative position of the sun in sky. Once they have it drawn on paper, they can measure it to be 60 degrees.

# Explain

Have students convene to share their findings. Some students may have reached different results depending on which way they measured (which directional orientation they started with). See if the students can figure out why their numbers are different.

Ensure that students understand that the sun is directly overhead in the middle of the day (this is the right angle).

Explain that the sun rises in the east and moves through the acute angles in the morning, passes the right angle around noon and moves through the obtuse angles in the afternoon and evening.

Ask students to write down an obtuse angle that they might see from the sun in the afternoon.

# Elaborate

Have students work independently to identify times of the day when the garden and/or roof (for solar panels) would experience shade.

Have students sketch the angles which will experience shade, measure them, and label the degrees and whether they are acute, obtuse, or right.

# Evaluate

As an exit ticket, give students the following problem to solve: Your school is installing solar panels but they can only face east or west. The sun is in the shade from the angles of 15 degrees to 65 degrees and again from 120 degrees to 135 degrees. Which direction should the panels be installed to get the most sunlight? Explain why using sketches, diagrams and/or words.

# Extensions and Connections

Create models of solar panels and monitor the amount of sun they get during the day.

Or

Bring in a local company who works with solar panel installation to discuss the steps that go into the work.

Or

Take a tour of local homes or businesses with solar panels and observe placement.

Or

Collect data about the angle of the sun at the same point on school grounds over the course of a month or school year. Have students make observations about the change in angle of the sun at different time of day. This can link to the work they will do in 5th grade.

# Resources

Explore jobs and reports related to solar panels such as:

• Breaking into the Solar Industry