The term for a line intercepting the y-axis is a y-intercept. In the equation y=mx+b, which is slope-INTERCEPT form, b is the y-intercept. Once again, the answer to your question is a y-intercept.
intersecting lines
Mutually Perpendicular
The phrase is a "conic section".
Those are known as conic section, and they are described by equations of degree 2.
area
1
intersecting lines
line
line segment
The description given fits that of a right angle triangle
line segment
Mutually Perpendicular
Altitude
co linear
altitude
i agree
The term that describes the intersection between two finite planes is a "line." When two planes intersect, they typically do so along a straight line, assuming the planes are not parallel. This line represents all the points that lie in both planes simultaneously.