Symmetry in regular polygons | Symmetry | Assessment | English | Grade 7

A figure has a(n) __________, if there is a line about which the figure may be folded so that the two parts of the figure will coincide with each other.

• line symmetry

• rotational symmetry

• axis

Tags

CCSS.4.G.A.3

Which of the following are mirror reflections of each other?

• 
• 
• 
• 

Tags

CCSS.4.G.A.3

The number of lines of symmetry in an equilateral triangle is ______.

• 0

• 1

• 2

• 3

Answer explanation

A triangle in which the length of all the three sides are equal is called an equilateral triangle. Hence, an equilateral triangle is a regular polygon. We know that the number of lines of symmetry in a regular polygon is equal to the number of sides of the polygon. So equilateral triangle has 3 lines of symmetry. Hence, option 4 is the right answer.

Tags

CCSS.4.G.A.3

How many lines of symmetry are there in the adjoining figure?

• 16

• 9

• 8

• 7

Answer explanation

The given figure is a regular octagon which has 8 lines of symmetry. Hence option 2 is the right answer.

Tags

CCSS.4.G.A.3

Which of the following letters have more than 2 lines of symmetry?

• H

• Z

• O

• E

Answer explanation

A vertical line and horizontal line divides the letter H into two identical parts. So, the letter H has exactly 2 lines of symmetry. A vertical line divided letter Z into two identical parts. Hence, the letter Z has 1 line of symmetry. Letter E also has one line of symmetry. But in letter O the vertical line, horizontal line and the diagonal lines divide the letter O into into two equal parts. Hence, letter O has more than two lines of symmetry.

Tags

CCSS.4.G.A.3

Which of the following lines divide the given rectangle into two mirror halves?

• Only BF

• Only HD

• Both AE and CG

• Both BF and HD

Answer explanation

The vertical line BF divides the rectangle into two mirror halves. Therefore, BF is a line of symmetry. Similarly, the horizontal line HD also divides the rectangle into mirror halves. Hence, HD is also a line of symmetry. But the diagonal lines AE and CG don't divide the rectangle into two mirror halves. Hence BF and HD divide the rectangle into 2 mirror halves. Hence option 4 is the right answer.

Tags

CCSS.4.G.A.3

In the given figure, the mirror line (i.e., the line of symmetry) is given as a dotted line. Copy the figure given here in your notebook and complete it by performing reflection in the dotted (mirror) line. Did you complete the figure?

• Yes

• No

Answer explanation

Tags

CCSS.4.G.A.3