Cross Bearings: Two Lines Find the Control

Each hidden control comes with two bearings from two known points; where the two lines cross, that's the control. Trios practice following a bearing accurately and the idea of fixing a position by triangulation.

How to play

1. Review: to follow a bearing, set the compass, pick a far object on that line and walk to it (5 min).
2. Demo with one control: one trio walks the bearing from pole A, another from pole B, and everyone sees where they cross (5 min).
3. In trios, find four controls using their two-bearing cards (15 min).
4. Reverse challenge: each trio places a cone, takes the bearings from A and B and gives them to another trio to find (8 min).
5. Wrap-up: where did accuracy slip and how to fix it (2 min).

Rules

• Poles A and B stay put all class.
• Walk the bearing, no running, looking ahead rather than at the compass.
• Each trio member takes a role each time: compass, guide and recorder.
• Stay away from fences and metal goals when taking bearings.

Variations

Adaptations

• Wheelchair users: poles on flat ground and the trio picks accessible controls.
• Low vision: act as recorder, or hold the compass with a partner describing the far object.
• Hesitant students: start as guide, who just walks to the marked object.

Learning goals

• Follow a bearing accurately.
• Understand how two bearings fix a position.
• Share roles and cooperate in a trio.

Equipment for a class of 25

• baseplate compasses: 10
• poles: 4
• orienteering markers: 8
• bearing cards: 10

Teacher tip

Work out the bearings yourself the day before and round them to 5 degrees. If you don't have markers, colored bottle caps or small cones work.

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