RightTrianglesTest.java

package com.spun.triangles.test;

import static org.junit.Assert.assertEquals;

import java.util.Random;

import org.junit.Test;

/**
 * Theory based kata
 * Level easy: do it
 * Level expert: do not use Math or StrictMath
 * @author llewellyn
 *
 */

public class RightTrianglesTest
{
  @Test
  public void testProblemSpaceBelow1000()
  {
    for (int a = 1; a < 1000; a++)
    {
      for (int b = a; b < 1000; b++)
      {
        double hypotenuse = RightTriangle.getHypotenuseFor(a, b);
        assertHypotenuse(a, b, hypotenuse);
      }
    }
  }
  @Test
  public void testProblemSpace()
  {
    Random r = new Random();
    for (int i = 1; i < 100000; i++)
    {
      int a = r.nextInt(Integer.MAX_VALUE);
      int b = r.nextInt(Integer.MAX_VALUE);
      double hypotenuse = RightTriangle.getHypotenuseFor(a, b);
      assertHypotenuse(a, b, hypotenuse);
    }
  }
  private void assertHypotenuse(double a, double b, double hypotenuse)
  {
    double aa = a * a;
    double bb = b * b;
    double cc = hypotenuse * hypotenuse;
    String message = String.format(
        "a^2 + b^2 != c^2\n" + "%s^2 + %s^2 != %s^2\n" + "%s + %s != %s\n" + "%s != %s", a, b, hypotenuse, aa, bb,
        cc, (aa + bb), cc);
    double delta = hypotenuse * 0.0001;
    assertEquals(message, aa + bb, cc, delta);
  }
}

class RightTriangle
{
  public static double getHypotenuseFor(double a, double b)
  {
    return 0;
  }
}

Make line 60 throw a Not Implemented exception, so it's obvious where we should be coding.