sides of a triangle are in the ratio 12:17:25 and its perimeter is 540 find its area
Answers
- Area of triangle is 9000.
Explanation:
Given:-
- Sides of triangle are in ratio 12:17:25 .
- Perimeter of triangle is 540.
To find:-
- Area of triangle.
Solution:-
Let, Sides of triangle by 12x, 17x and 25x.
Perimeter of triangle = a + b + c
In which,
- a, b and c are sides of triangle.
So,
➝ 12x + 17x + 25x = 540
➝ 54x = 540
➝ x = 540/54
➝ x = 10
Sides will be
12x = 12 × 10 = 120
17x = 17 × 10 = 170
25x = 25 × 10 = 250
- We do not have height of triangle. So, we can't use 1/2 × b × h. We will use heron's Formula for area.
We know that,
Formula of heron's formula is :
Area of triangle = √s(s - a)(s - b)(s - c)
In which,
- S is semi-perimeter of triangle.
- a, b and c are sides of triangle.
So,
s = Perimeter/2
s = 540/2
s = 270
Semi-perimeter is 270.
Put s and sides of triangle in formula:
➝ √270 (270 - 120)(270 - 170)(270 - 250)
➝ √270 × 150 × 100 × 20
➝√2×3×3×3×5×2×3×5×5×2×2×5×5×2×2×5
➝ 2 × 2 × 2 × 3 × 3 × 5 × 5 × 5
➝ 9000
Therefore,
Area of triangle is 9000.
Sides of triangle -
12 : 17 : 25
Perimeter of triangle -
540
Let sides be,
12x , 17x , 25x
So,
12x + 17x + 25x = 540
54x = 540
x = 540
x = 540 / 54
x = 10
So sides,
12x = 12 × 10 = 120
17x = 17 × 10 = 170
25x = 25 × 10 = 250
Using Heron's Formula -
Area = √s(s-a) (s-b) (s-c)
Semi perimeter = Perimeter / 2
Semi perimeter = 540 / 2
Semi perimeter = 270
Then area
√270(270-120) (270-170) (270-250)
√270 × 150 × 100 × 20
√2 × 3× 3 × 3 × 5 × 2 × 3 × 5 × 5 × 2 × 2 × 5 × 5 × 2 × 2 × 5
2 × 2 × 2 × 3 × 3 × 5 × 5
9000