3. If sides
of the triangle are in the
ratio 6:4:5 and its perimeter is
90 on then find the area?
Answers
Answer: 357.17 unit sq.
Step-by-step explanation:Since the ratio is 6:4:5 , let the sides be 6x , 4x and 5x .
therefore, 6x + 4x + 5x = 90
15x = 90
x = 90÷15
x = 6
sides are 36 , 24 and 30
after finding the sides we will find the area by using the heron's formula
area = √s(s-a)(s-b)(s-c)
where s = perimeter/2
area = √(45)(45-36)(45-24)(45-30)
= √45×9×21×15
= 45×3√7
= 135×2.645
= 357.17
AnswEr :-
• Area of the triangle is 135√7 units.
Given :-
• Sides of a triangle are in ratio 6:4:5.
To Find :-
• Area of the triangle.
SoluTion :-
Sides of the triangle are in ratio 6:4:5
Put x in the ratio
Then,
Sides are 6x , 4x , 5x
Perimeter of a triangle = sum of all sides.
★According to the question
» 6x + 4x + 5x = 90
→ 15x = 90
→ x = 90/15
→ x = 6
Put the value of x in the ratio.
6x = 6 × 6 = 36
4x = 4 × 6 = 24
5x = 5 × 6 = 30
Here,
• a = 36
• b = 24
• c = 30
We've to find semi - perimeter of the triangle.
★ Formula for finding semi - perimeter ( S ) of the triangle is
» S = a + b + c / 2
→ S = 36 + 24 + 30 / 2
→ S = 90/2
→ S = 45
★ Formula for finding area of the triangle is
» √s (s - a) (s - b) (s - c)
→ √45 (45 - 36) (45 - 24) (45 - 30)
→ √45 × 9 × 21 × 15
→ 135√7 units