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 90Â°.

**Draw the following plane figures.**

Question 1.

a. triangle

Answer:

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

Answer:

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

Answer:

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

Answer:

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

Answer:

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

Answer:

Square corner is nothing but having four sides with similar length and the four corners which exist at right angles (90 degrees) .The number of possible square corners for the given shape such as Circle, Rectangle , Right angle Triangle , Square and a Triangle are as shown Below.

Question 4.

number of other corners for the Given Shapes Circle, Rectangle , Right angle Triangle , Square and a Triangle are as shown Below.

Answer: