Training Guide: Programming in HTML5 with JavaScript and CSS3 Ebook

Answers

This section contains the answers to the lesson review questions in this chapter.

Lesson 1

1. Correct answer: C
   A. Incorrect: The getContext method requires the 2d parameter, and there is no rectangle
   method on the context object.
   B. Incorrect: To draw on the canvas, you need to execute the getContext method to get a
   reference to a context object, and there is no rectangle method on the canvas object.
   C. Correct: This is the correct code, in which a reference to a context object is obtained by
   calling the getContext method with the 2d parameter.
   D. Incorrect: The getContext method requires the 2d parameter.


2. Correct answer: B
   A. Incorrect: The arcTo method typically draws a line and an arc. Although it could accom-
   plish the task, it would be very difficult in comparison to the arc method.
   B. Correct: Using the arc method is the easiest way to accomplish this task.
   C. Incorrect: The circle method does not exist.
   D. Incorrect: The dot method does not exist.

Lesson 2

1. Correct answer: D
   A. Incorrect: HTML is derived from SGML, but the
   B. Incorrect: HTML is used for webpages, but the
   C. Incorrect: XHTML is used for webpages, but the
   D. Correct: The


2. Correct answer: C
   A. Incorrect: The zoom attribute does not exist.
   B. Incorrect: The window attribute does not exist.
   C. Correct: The viewBox attribute provides a window into the drawing and enables zoom
   capabilities.
   D. Incorrect: The zoomWindow attribute does not exist.