Each shape (polygon) is divided into triangles by drawing diagonals (that do not cross) from one vertex. Number of sides s 4 5 6 7 8 Number of triangles t 2 How many triangles are in a 15 sided shape?

Given figure: In the above figure, we observe that, For fourth polygon, 7 sides and 5 triangles and for fifth polygon 8 sides and 6 triangles. Now, we can find the rule: Number of triangles = Number of sides - 2 So, the generalisation formula is t = n - 2 , where t is the number of triangles and s is the number of sides. Filling the table using the rule t = n - 2 , we get, Number of sides s 4 5 6 7 8 Pattern n - 2 4 - 2 = 2 5 - 2 = 3 6 - 2 = 4 7 - 2 = 5 8 - 2 = 6 Number of triangles t 2 3 4 5 6 Now, number of triangles in a 15 sided shape t = n - 2 = 15 - 2 = 13 Hence, 13 triangles are there in a 15 sided shape.

Each shape (polygon) is divided into triangles by drawing diagonals (that do not cross) from one vertex. Number of sides s 4 5 6 7 8 Number of triangles t 2 How many triangles are in a 20 sided shape?

Given figure: In the above figure, we observe that, For fourth polygon, 7 sides and 5 triangles and for fifth polygon 8 sides and 6 triangles. Now, we can find the rule: Number of triangles = Number of sides - 2 So, the generalisation formula is t = n - 2 , where t is the number of triangles and s is the number of sides. Filling the table using the rule t = n - 2 , we get, Number of sides s 4 5 6 7 8 Pattern n - 2 4 - 2 = 2 5 - 2 = 3 6 - 2 = 4 7 - 2 = 5 8 - 2 = 6 Number of triangles t 2 3 4 5 6 Now, number of triangles in a 20 sided shape t = 20 - 2 = 20 - 2 = 18 Hence, 18 triangles are there in a 20 sided shape.

S K Gupta and Anubhuti Gangal Solutions for Exercise 2: Exercise

Author:S K Gupta & Anubhuti Gangal

S K Gupta Mathematics Solutions for Exercise - S K Gupta and Anubhuti Gangal Solutions for Exercise 2: Exercise

Attempt the free practice questions from Exercise 2: Exercise with hints and solutions to strengthen your understanding. ICSE NumbersWiz 6 solutions are prepared by Experienced Embibe Experts.

Questions from S K Gupta and Anubhuti Gangal Solutions for Exercise 2: Exercise with Hints & Solutions

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6th ICSE

IMPORTANT

ICSE NumbersWiz 6>Chapter 11 - Introduction to Algebra>Exercise>Q 5

Construct the pattern shown below. How many matchsticks are needed to make a group of $20$ squares?

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Let $s$ be the number of squares and $m$ be the number of matchsticks.

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6th ICSE

IMPORTANT

ICSE NumbersWiz 6>Chapter 11 - Introduction to Algebra>Exercise>Q 5

Construct the pattern shown below. How many matchsticks are needed to make a group of $75$ squares?

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Let $s$ be the number of squares and $m$ be the number of matchsticks.

MEDIUM

6th ICSE

IMPORTANT

ICSE NumbersWiz 6>Chapter 11 - Introduction to Algebra>Exercise>Q 6

Construct the pattern shown below.

Question Image

Let $r$ be the number of rectangles and $m$ be the number of matchsticks

Complete the following table and the rule: $m =$

Number of rectangles $(r)$	$1$	$2$	$3$	$4$
Number of matchsticks $(m)$	$6$
Pattern	$5 \times$ _____ $+$ _____

MEDIUM

6th ICSE

IMPORTANT

ICSE NumbersWiz 6>Chapter 11 - Introduction to Algebra>Exercise>Q 6

Construct the pattern shown below. How many matchsticks are needed to make a group of $8$ rectangles?

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Let $r$ be the number of rectangles and $m$ be the number of matchsticks.

MEDIUM

6th ICSE

IMPORTANT

ICSE NumbersWiz 6>Chapter 11 - Introduction to Algebra>Exercise>Q 6

Construct the pattern shown below. How many matchsticks are needed to make a group of $20$ rectangles?

Question Image

Let $r$ be the number of rectangles and $m$ be the number of matchsticks.

MEDIUM

6th ICSE

IMPORTANT

ICSE NumbersWiz 6>Chapter 11 - Introduction to Algebra>Exercise>Q 6

Construct the pattern shown below. How many matchsticks are needed to make a group of $58$ rectangles?

Question Image

Let $r$ be the number of rectangles and $m$ be the number of matchsticks.

MEDIUM

6th ICSE

IMPORTANT

ICSE NumbersWiz 6>Chapter 11 - Introduction to Algebra>Exercise>Q 7

Each shape (polygon) is divided into triangles by drawing diagonals (that do not cross) from one vertex.

Question Image

Number of sides $(s)$	$4$	$5$	$6$	$7$	$8$
Number of triangles $(t)$	$2$

How many triangles are in a $15$ sided shape?

MEDIUM

6th ICSE

IMPORTANT

ICSE NumbersWiz 6>Chapter 11 - Introduction to Algebra>Exercise>Q 7

Each shape (polygon) is divided into triangles by drawing diagonals (that do not cross) from one vertex.

Question Image

Number of sides $(s)$	$4$	$5$	$6$	$7$	$8$
Number of triangles $(t)$	$2$

How many triangles are in a $20$ sided shape?

S K Gupta and Anubhuti Gangal Solutions for Exercise 2: Exercise

S K Gupta Mathematics Solutions for Exercise - S K Gupta and Anubhuti Gangal Solutions for Exercise 2: Exercise

Questions from S K Gupta and Anubhuti Gangal Solutions for Exercise 2: Exercise with Hints & Solutions

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