Question

A traffic signal board, indicating ‘SCHOOL AHEAD’, is an equilateral triangle with side ‘a’. Find the area of the signal board, using Heron’s formula. If its perimeter is 180 cm, what will be the area of the signal board?

Solution

'a' = a
'b' = a
'c' = a
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Area of the signal board
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Perimeter = 180 cm
$rightwards double arrow$ 'a' + 'b' + 'c' = 180
$rightwards double arrow$ a + a + a = 180
$rightwards double arrow$ 3a = 180
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$rightwards double arrow space space space$ a = 60 cm
$therefore$ Area of the signal board $equals fraction numerator square root of 3 over denominator 4 end fraction straight a squared$
$equals fraction numerator square root of 3 over denominator 4 end fraction left parenthesis 60 right parenthesis squared equals 900 square root of 3 space cm squared$
Alternatively,
$space space space space space straight s space equals fraction numerator 3 straight a over denominator 2 end fraction equals 3 over 2 left parenthesis 60 right parenthesis equals 90 space cm$
Area of the signal board
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Question

Wired Faculty App

The triangular side walls of a flyover have been used for advertisements. The sides of the walls are 122 m, 22 m and 120 m (see figure). The advertisements yield an earning of र5000 per m² per year. A company hired one of its walls for 3 months. How much rent did it pay?

Solution

a =122 m
b = 22 m
c = 120 m
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1 year =12 months
V Rent for 12 months per m²= र 5000

$therefore space$ Rent for 1 month per m² = र $5000 over 2$
$therefore$ Rent for 3 months of 1320 m²
$equals space र 5000 over 12 cross times 3 equals space र space 1250$

$therefore space space$ Rent for 3 months of 1320 m²
= र (1250 x 1320)
= र 1650000.

Question

Wired Faculty App

There is a slide in a park. One of its side walls has been painted in some colour with a message “KEEP THE PARK GREEN AND CLEAN”. If the sides of the wall are 15 m, 11 m and 6 m, find the area painted in colour.

Solution

a = 15 m
b = 11 m
c = 6 m
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$therefore$ Area painted in colour
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Question

Wired Faculty App

Find the area of a triangle two sides of which are 18 cm and 10 cm and the perimeter is 42 cm.

Solution

a = 18 cm
b = 10 cm Perimeter - 42 cm
⇒ a + b + c = 42
⇒ 18 + 10 + c = 42
⇒ 28 + c = 42
⇒ c = 42 – 28
⇒ c = 14 cm
$space space space space space space space space space space space space space straight s equals 42 over 2 equals 21 space cm$
$therefore space space space space space$ Area of the triangle
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A traffic signal board, indicating ‘SCHOOL AHEAD’, is an equilateral triangle with side ‘a’. Find the area of the signal board, using Heron’s formula. If its perimeter is 180 cm, what will be the area of the signal board?

The triangular side walls of a flyover have been used for advertisements. The sides of the walls are 122 m, 22 m and 120 m (see figure). The advertisements yield an earning of र5000 per m² per year. A company hired one of its walls for 3 months. How much rent did it pay?

There is a slide in a park. One of its side walls has been painted in some colour with a message “KEEP THE PARK GREEN AND CLEAN”. If the sides of the wall are 15 m, 11 m and 6 m, find the area painted in colour.

Find the area of a triangle two sides of which are 18 cm and 10 cm and the perimeter is 42 cm.

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For Daily Free Study Material Join wiredfaculty

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Download Android App

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Statistics

A traffic signal board, indicating ‘SCHOOL AHEAD’, is an equilateral triangle with side ‘a’. Find the area of the signal board, using Heron’s formula. If its perimeter is 180 cm, what will be the area of the signal board?

The triangular side walls of a flyover have been used for advertisements. The sides of the walls are 122 m, 22 m and 120 m (see figure). The advertisements yield an earning of र5000 per m2 per year. A company hired one of its walls for 3 months. How much rent did it pay?

There is a slide in a park. One of its side walls has been painted in some colour with a message “KEEP THE PARK GREEN AND CLEAN”. If the sides of the wall are 15 m, 11 m and 6 m, find the area painted in colour.

Find the area of a triangle two sides of which are 18 cm and 10 cm and the perimeter is 42 cm.

Mock Test Series

NCERT Sample Papers

Entrance Exams Preparation

The triangular side walls of a flyover have been used for advertisements. The sides of the walls are 122 m, 22 m and 120 m (see figure). The advertisements yield an earning of र5000 per m² per year. A company hired one of its walls for 3 months. How much rent did it pay?