Q-Sides of a triangle are in the ratio of 12:17:25 and its perimeter is 540 cm. Find its area.
Ans-25cm true or false
Answers
Question
- Sides of a triangle are in the ratio of 12:17:25 and its perimeter is 540 cm. Find its area?
Given
- Sides of triangle in ratio 12:17:25
- Perimeter = 540cm
To Calculate
- Area __?
Explanation
Sides Given in ratio 12:17:25
Let Sides are 12x, 17x,25x
Where
perimeter = 540 cm
➥ 540 = 12x+17x+25x
➥ 540 = 54x
➥ x= 540/54
➥ x= 10
Sides are : -
12x = 12×10 = 120cm
17x = 17×10 = 170cm
25x = 25×10 = 250cm
➥ 120+ 170+250 / 2
➥ 540/2
➥ 270
☆ Using Heron's formula ☆
Area = √S(s-a)(s-b)(s-c)
➥ √270(270-120)(270-170)(270-250)
➥ √270(150)(100)(250)
➥√ 270×150×100×250
➥ √ (27×15×2)(10)⁵
➥√ (27×30)(10)⁵
➥ √(27×3)(10)⁶
➥√(81)×(10)⁶
➥√9²= √10⁶
➥9×(10⁶)½
➥ 9×10³
➥ 9000cm²
- Your answer is False
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1) In a right ΔABC
ar(ΔABC ) = 1/2×b×h
2) In an equilateral triangle of side a
i) Height = (√3/2 a) units
ii) Area = ( √3/4 a²) sq. units
iii) perimeter = 3a units
3) For isosceles ΔABC in which AB= AC = a and BC =b
i) Height = √4a²-b² / 2 units
ii) Area = (1/4b √4a²-b² sq. units
iii) perimeter = 2a+b units
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