Sponsor Area
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?
'a' = a
'b' = a
'c' = a
Area of the signal board
Perimeter = 180 cm
'a' + 'b' + 'c' = 180
a + a + a = 180
3a = 180
a = 60 cm
Area of the signal board 
Alternatively,
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?
a =122 m
b = 22 m
c = 120 m
1 year =12 months
V Rent for 12 months per m2= र 5000
Rent for 1 month per m2 = र
Rent for 3 months of 1320 m2
Rent for 3 months of 1320 m2
= र (1250 x 1320)
= र 1650000.
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.
a = 15 m
b = 11 m
c = 6 m
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.
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
Area of the triangle
Sponsor Area
Mock Test Series
Mock Test Series