RectangularCollisionTest.cs

bool CollisionTest()
{
    var aRectangle = new Rectangle(_a.X, _a.Y, _a.Width, _a.Height);
    var bRectangle = new Rectangle(_b.X, _b.Y, _b.Width, _b.Height);

    return Intersects(aRectangle, bRectangle);
}

bool Intersects(Rectangle a, Rectangle b)
{
    return (b.X < a.X + a.Width) && (a.X < b.X + b.Width) &&
           (b.Y < a.Y + a.Height) && (a.Y < b.Y + b.Height);
}