<dependencies> <dependency> <groupId>org.jbox2d</groupId> <artifactId>jbox2d-library</artifactId> <version>2.3.1</version> </dependency> </dependencies> import org.jbox2d.common.Vec2; import org.jbox2d.common.Vec3; import org.jbox2d.pooling.normal.Vec2Pool; import org.jbox2d.pooling.normal.Vec3Pool; public class TriangleCalculator { public static void main(String[] args) { Vec2 vertexA = new Vec2(0, 0); Vec2 vertexB = new Vec2(3, 0); Vec2 vertexC = new Vec2(0, 4); float sideAB = vertexA.sub(vertexB).length(); float sideBC = vertexB.sub(vertexC).length(); float sideCA = vertexC.sub(vertexA).length(); Vec2 vectorAB = vertexA.sub(vertexB); Vec2 vectorBC = vertexB.sub(vertexC); Vec2 vectorCA = vertexC.sub(vertexA); float angleA = vectorBC.negateLocal().angle(vectorCA); float angleB = vectorCA.negateLocal().angle(vectorAB); float angleC = vectorAB.negateLocal().angle(vectorBC); } }