What countrys flag is black yellow and red?
No context provided
What country's flag is black yellow and red, in vertical stripes?
Belgium
No context provided
What country's flag is black yellow and red, in horizontal stripes?
Germany
No context provided
What country's flag is black yellow and red, with a machete on it?
Angola
List of flags by color combination
https://en.wikipedia.org/wiki/List%20of%20flags%20by%20color%20combination
 It is split horizontally into an upper red half and a lower black half with an emblem resting at the center. It features a yellow half gear wheel crossed by a machete and crowned with a star.
Flag of Angola
Various countries utilize black, yellow and red on their flags. Among them, Belgium has a flag that contains three vertical lines, while Germany uses one that has three horizontal stripes and orders the colors differently, with the red used for the middle and the yellow used in the bottom. The flag of Angola also uses the colors. It is split horizontally into an upper red half and a lower black half with a yellow half gear wheel crossed by a machete and crowned with a star in the middle.