2.
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 Fig. 12.9). The advertisements yield an
earning of 5000 per mº per year. A company hired one of its walls for 3 months. How
much rent did it pay?
Before, finding the answer. Let’s find out on how we can find the answer.
[tex]\sf \sqrt{s (s-a) (s-b) (s-c)}[/tex]
Where,
S = Semi-perimeter
A = Side 1
B = Side 2
C = Side 3
___________________
Given :
To find :
Solution :
Semi-perimeter = [tex]\sf \dfrac{a + b + c}{2}[/tex]
= [tex]\sf \dfrac{122 + 22 + 120}{2}[/tex]
= [tex]\sf \dfrac{264}{2}[/tex]
= 132 m
Area of Triangular side walls = [tex]\sf \sqrt{s (s-a) (s-b) (s-c)}[/tex]
= [tex]\sf \sqrt{132 (132-122) (132-22) (132-120)}[/tex]
= [tex]\sf \sqrt{132 \times (10) \times (110) \times (12)}[/tex]
= [tex]\sf \sqrt{1742400}[/tex]
= 1320 m²
∴ Area of the Wall will be 1320 m².
⇒ Then total earning will be = Total area × per m² cost.
Total Earning = 5000 × 1320
→ Rs. 66,00,000
⇒ So, further it is said that the company hired one of its walls for 3 months. Its rent for 3 months will be :
= Total earnings × 3/12
= 66,00,000 × 3/12
→ Rs. 16,50,000