Question

Very Short Answer Type Questions :-

1. The side of an equilateral triangle is 4 cm. What is its perimeter?

2. The perimeter of an equilateral triangle is 18 cm. What is length of its side?

3. The perimeter of an isosceles triangle is 14 cm. If each of the equal sides is 5 cm, then what is the length of its base?

4. Each of the equal sides of an isosceles triangle is 4 cm. What is its base if its perimeter is 13 cm?

5. The perimeter of a square is 24 cm. What is the length of its side?

6. If the side of a square is 8 cm long, what is its perimeter?

7. If the perimeter of a square is 26 cm, then what is the length of its side?

8. If the side of a square is 10.5 cm, then what is its perimeter?

9. The length and breadth of a rectangle are 12 cm and 8 cm respectively. What is its perimeter?

10. The perimeter of a rectangle is 20 cm. If its breadth is 4.5 cm, then what its length?

11. The length of a rectangle is twice its breadth. If its perimeter is 18 cm, then what is its breadth?

12. If the breadth and perimeter of a rectangle are 2 cm and 14 cm respectively. Find its length.​

Answer 1

Answer 1

Given:

⊙Side of equilateral triangle is 4cm

Solution:

As we know that all sides in an equilateral triangle are equal so:

$\small\boxed{ \sf&#10029 Perimeter \: of \: equilateral \: triangle= Sum\:of\:all\:sides }$

$\small{ \sf Perimeter \: of \: equilateral \: triangle= 4cm+4cm+4cm }$

$\small{ \sf Perimeter \: of \: equilateral \: triangle= 12cm }$

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Answer 2

Given:

⊙Perimeter of equilateral triangle is 18cm.

Solution:

As we know that sides of equilateral triangle are always equal.

Let us suppose sides of triangle be x.

$\small\boxed{\sf&#10029 \:Perimeter\: of\: ∆=Sum \:of \:all \:sides}$

⟹18cm=x+x+x

⟹18cm=3x

$\sf⟹\frac{18}{3}=x$

⟹6cm=x

Hence the sides of equilateral triangle are 6cm each.

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Answer 3

Given:

⊙Perimeter of isosceles∆ is 14cm

⊙Each equal side is 5cm

Solution:

As we know that 2 sides of isoscele ∆ are equal.

So let us suppose the base (unequal side) be x .

$\small\boxed{\sf &#10029\: Perimeter\: of \:∆=Sum\: of\: all\: sides}$

⟹14cm =(Equal sides)+base

⟹14cm=(5+5)+x

⟹14cm=10+x

⟹14cm-10=x

⟹4cm=x

So base of triangle is 4cm

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Answer 4

Given:

⊙Perimeter of isosceles triangle is 13cm.

⊙Equal side is 4cm

Solution:

Let us suppose base (unequal side) be x.

$\small\boxed{\sf &#10029\: Perimeter\: of \:∆=Sum\: of\: all\: sides}$

13cm=(Equal sides)+base

$\sf\implies 13cm=(4+4)+x$

$\sf\implies 13cm=8+x$

$\sf\implies 13cm-8=x$

$\sf\implies 5cm=x$

Hence the base of triangle is 5cm.

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Answer 5

Given:

⊙Perimeter of square=24cm

Solution:

As we have to find the side of square so we can easily find it by applying formula of perimeter of square.

$\small\boxed{\sf &#10029\: Perimeter\: of \: square=4×Side}$

$\sf\implies 24cm=4×Side$

$\sf\implies \frac{24cm}{4}=Side$

$\sf\implies 6cm=Side$

Hence the side of square is 6cm.

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Answer 6

Given:

⊙Side of square is 8cm.

Solution:

To find the perimeter of square,we can simply find it by applying formula or perimeter of square.

$\boxed{\sf&#10029 Perimeter\:of\:square=4×Side}$

${\sf Perimeter\:of\:square=4×8cm}$

${\sf Perimeter\:of\:square=32cm}$

Hence the perimeter of square is 32cm.

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Answer 7

Given:

⊙Perimeter of Square is 26cm.

Solution:

$\boxed{\sf&#10029 Perimeter\:of\:square=4×Side}$

$\sf\implies 26cm=4×Side$

$\sf\implies \frac{26cm}{4}=Side$

$\sf\implies 6.5cm=Side$

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Answer 8

Given:

⊙Side of square is 10.5cm

Solution:

$\boxed{\sf&#10029 Perimeter\:of\:square=4×Side}$

$\sf\implies 4×10.5cm$

$\sf\implies 42cm$

So perimeter is 42cm

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Answer 9

Given:

⊙Length of rectangle=12cm

⊙Breadth of rectangle=8cm

Solution:

$\boxed{\sf&#10029 Perimeter\:of\: rectangle=2(L+B)}$

$\sf Perimeter\:of\:rectangle=2(12+8)$

Perimeter of rectangle=2(20)

Perimeter of rectangle=40cm

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Answer 10

Given:

⊙Perimeter of rectangle=20cm

⊙Breadth=4.5cm

Solution:

$\boxed{\sf&#10029 Perimeter\:of\: rectangle=2(L+B)}$

20cm=2(L+4.5)

20/2=L+4.5

10-4.5=L

5.5cm=L

length of rectangle=5.5cm

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Answer 11

Given:

⊙ Perimeter of rectangle=18cm

⊙Length is twice of Breadth

Solution:

Let breadth of rectangle be x

So length is 2x

$\boxed{\sf&#10029 Perimeter\:of\: rectangle=2(L+B)}$

18cm=2(2x+x)

18cm=2(3x)

18cm=6x

18/6=x

3=x

So breadth is x =3cm

Length=2x=6cm.

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Answer 12

Given:

⊙Breadth of rectangle is 2cm

⊙Perimeter =14cm

Solution:

$\boxed{\sf&#10029 Perimeter\:of\: rectangle=2(L+B)}$

14cm=2(L+2)

14cm/2=L+2

7cm=L+2

7-2cm=L

5cm=L

So length of rectangle is 5cm

Answer 2

Answer:

1) Perimeter of triangle is 12 cm.

2) The length of its side is 6 cm.

3) The length of the base is 4 cm.

4) Its base is 5 cm.

5) The length of its side is 6 cm.

6) The perimeter of square is 32 cm.

7) The length of its side is 6.5 cm.

8) The perimeter of the square is 42 cm.

9) The perimeter of the rectangle is 40 cm.

10) The length of rectangle is 5.5 cm.

11) The breadth of rectangle is 3 cm.

12) The length of rectangle is 5 cm.

Step-by-step explanation:

1) Given: Side of equilateral triangle = 4 cm.

w.k.t., perimeter of equilateral triangle of side a is 3a.

⇒ Perimeter of triangle = 3×4

⇒ Perimeter of triangle = 12 cm

2) Given: Perimeter of equilateral triangle = 18 cm.

Let the side of equilateral triangle be y.

w.k.t., perimeter of equilateral triangle of side a is 3a.

⇒ Perimeter of triangle = 3×y

⇒ 18 =3y

⇒ y = 18/3 = 6 cm

3) Given: Perimeter of isosceles triangle = 14 cm and length of equal sides = 5 cm.

Let the length of base be y.

w.k.t., perimeter of isosceles triangle = 2(length of equal sides) + (length of third side)

⇒ 14 = 2×5 + y

⇒ 14 = 10 + y

⇒ y = 14-10 = 4 cm

4) Given: Perimeter of isosceles triangle = 13 cm and length of equal sides = 4 cm.

Let the length of base be y.

w.k.t., perimeter of isosceles triangle = 2(length of equal sides) + (length of third side)

⇒ 13 = 2×4 + y

⇒ 13 = 8 + y

⇒ y = 13-8 = 5 cm

5) Given: Perimeter of square = 24 cm.

Let the length of its side be y.

w.k.t., perimeter of square of side length a is 4a.

⇒ 24 = 4y

⇒ y = 24/4 = 6 cm

6) Given: Length of side of square = 8 cm.

w.k.t., perimeter of square of side length a is 4a.

⇒ Perimeter of square = 4×8

⇒ Perimeter of square = 32 cm

7) Given: Perimeter of square = 26 cm.

Let the length of its side be y.

w.k.t., perimeter of square of side length a is 4a.

⇒ 26 = 4y

⇒ y = 26/4 = 6.5 cm

8) Given: Length of side of square = 10.5 cm.

w.k.t., perimeter of square of side length a is 4a.

⇒ Perimeter of square = 4×10.5

⇒ Perimeter of square = 42 cm

9) Given: Length of rectangle = 12 cm and breadth of rectangle = 8 cm.

w.k.t., perimeter of rectangle with length l and breadth b is 2(l+b).

⇒ Perimeter of rectangle = 2×(12+8)

⇒ Perimeter of rectangle = 2×20

⇒ Perimeter of rectangle = 40 cm

10) Given: Perimeter of rectangle = 20 cm and breadth of rectangle = 4.5 cm.

Let the length of the rectangle be y cm.

w.k.t., perimeter of rectangle with length l and breadth b is 2(l+b).

⇒ 20 = 2×(y+4.5)

⇒ 10 = y + 4.5

⇒ y = 10-4.5 = 5.5 cm

11) Given: Perimeter of rectangle = 18 cm and length of rectangle is twice its breadth.

Let the breadth of the rectangle be y cm.

⇒ Length of rectangle = 2y

w.k.t., perimeter of rectangle with length l and breadth b is 2(l+b).

⇒ 18 = 2×(y+2y)

⇒ 9 = 3y

⇒ y = 9/3 = 3 cm

12) Given: Perimeter of rectangle = 14 cm and breadth of rectangle = 2 cm.

Let the length of the rectangle be y cm.

w.k.t., perimeter of rectangle with length l and breadth b is 2(l+b).

⇒ 14 = 2×(y+2)

⇒ 7 = y + 2

⇒ y = 7-2 = 5 cm