Curriculum › Math ›Grade 4

Grade 4 Math · Level 4, Measurement, Area, Angles & Symmetry

Measure & Sketch Angles

How the lesson starts: Measure & Sketch Angles

1. Captain Mo's treasure map

   Ahoy! Captain Mo found a treasure map. It says, "Turn 70° at the palm tree." Polly the parrot squawks, "How do we measure that?" With a protractor! Let's learn to use one.

2. Read the scale

   Imagine the protractor's scale unrolled flat. The starting ray sits on 0. The second ray crosses the scale at 70. Count up from 0 to 70. The angle is 70°. Turn here, Captain!

3. How to measure

   Here's how to use a protractor. Put its center mark right on the vertex. Line up the starting ray with the 0. Follow that scale up, and read where the other ray crosses. If it crosses at 70, the angle is 70°!