# Spectrum Math Grade 3 Chapter 9 Lesson 1 Answer Key Plane Figures

Students can use the Spectrum Math Grade 3 Answer Key Chapter 9 Lesson 9.1 Plane Figures as a quick guide to resolve any of their doubts.

## Spectrum Math Grade 3 Chapter 9 Lesson 9.1 Plane Figures Answers Key

A plane figure is a flat surface.  Each side of a triangle, square, and rectangle is a line segment.
The point where two line segments meet is a corner or a square corner.
A square corner is a right angle. A right angle has a measure of 90°.

Draw the following plane figures.

Question 1.
a. triangle
A Triangle is kind of Polygon having three vertices and Sides. It is a shape generated if three straight lines are joines which are as Shown Below. b. rectangle
A rectangle is a kind of Quadrilateral and often called as Equiangular Quadrilateral. It’s Area is Calculated by multiplying the Both the Length and Width. c. square
It is a type of shape having four equal sides and vertices at an angle of 90 degrees. A Square is also a basic Quadrilateral. d. circle
A Universal shape containing huge sense and also a type of shape which doesn’t contain any corners or edges which is as shown Below. Complete the following.

Question 2.
number of sides The number of possible Sides for the given shapes such as Circle, Rectangle , Right angle Triangle , Square and a Triangle are as shown Below. Question 3.
number of square corners    