Question

the lenght of one side of a triangle is 7.2 cm the remaing two side meansure 5.3 each what type of triangle is it ? its perimeter​

Answer 1

Given

• One side of the triangle = 7.2 cm
• Other two sides = 5.3 cm

To find

• What type of triangle it is.
• Perimeter of the triangle

Solution

It is an isosceles triangle.

Reason :-

Isosceles triangle is the one in which two sides of the triangle are equal to each other and the third side is unequal and in this triangle two sides of length 5.3 cm are equal. So, it is an isosceles triangle.

Perimeter :-

Formula to be used :-

❖ Perimeter = 2a + b

where,

• a = two equal sides of the triangle
• b = third side of the triangle

Substituting the given values,

⟼ Perimeter = 2(5.3) + 7.2

⟼ Perimeter = 10.6 + 7.2

⟼ Perimeter = 17.8

∴ Perimeter of the isosceles triangle = 17.8 cm

_______________________________

More about Triangles :-

Equilateral triangle

• In this all sides of the triangle are equal to each other.

Area of equilateral triangle -

$\sf{\dfrac{\sqrt{3}}{4}a^2}$

Scalene triangle

• In this triangle all sides are unequal.

Heron's formula = $\sf{\sqrt{s(s - a)(s - b)(s - c)}}$

Answer 2

Given,

• The length of one side of triangle = 7.2 cm
• The length of other two sides= 5.3 cm

To prove,

• Perimeter of triangle = ?

Formula used,

• Perimeter of triangle = a + b + c

Solution,

As the two sides of the triangle are equal, it is considered as an isosceles triangle.

• a = 7.2 cm
• b = 5.3 cm
• c = 5.3 cm

Perimeter of triangle = a + b + c

= 7.2 + 5.3 + 5.3

= 17.8 cm

Therefore, 17.8 cm is the perimeter of triangle.