Math Question: Find the measure of angle ABC if angle ABD measures 60 degrees and angle DBC measures 40 degrees.
+
What is the general equation of an ellipse, considering its center (h,k), major and minor axes lengths (2a and 2b), and its horizontal or vertical orientation?
+
What is the smallest value of n that satisfies Fermat's theorem stating that there are no positive integer solutions to the equation x^n + y^n = z^n for n > 2?