Final answer:
The claim about World Major Axes being in mm and Minor Axes in degrees is false, as both are measures of length in an ellipse. A vector can indeed form a right angle triangle with its components, and Pythagorean theorem applies to vectors at right angles, but you cannot find the resultant vector's angle with only the individual angles known.
Step-by-step explanation:
The statement, "WORLD Major Axes are in mm while the Minor Axes are in degrees," is False. In physics and mathematics, an ellipse's major and minor axes are measures of its lengths, not a mix of length and angle units. The major axis is the longest diameter of the ellipse, while the minor axis is the shortest. The semi-major axis is half the length of the major axis, similar to the semi-minor axis being half of the minor axis.
Concerning vectors, it is True that a vector can form a right angle triangle with its x and y components. Moreover, if only the angles of two vectors are known without their magnitudes, you cannot definitively find the angle of their resultant addition vector, making the 'GRASP CHECK' statement False. However, if two vectors are at right angles to each other, you can use the Pythagorean theorem to calculate the length of the resultant vector, which is also True.
Kepler's Second Law, which pertains to the orbits of planets being ellipses, makes use of the concepts of major and minor axes but is not specifically relevant to the truth-value of the original statement about axes being measured in mixed units.