Question

1.The sides of a triangular plot are in the ratio of 3:5:7 and w its perimeter is 300 m. Find its area.
(a) 4 √30 (b) 8 √30 (c) 12 √30 (d) 16 √30
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Answer 1

Step-by-step explanation:

sides ratio = 3:5:7

let sides are 3x ,5x & 7x

perimeter = 300

3x + 5x + 7x = 300

15x = 300, x = 20

sides are 3x = 3(20) = 60m

,5x = 5(20) = 100 & 7x = 7(20) = 140m

semi perimeter of triangle

s=300/2 = 150m

by hero's formula

area of triangle =√[150(150-60)(150-100)(150-140)]

= √(150×90×50×10)

=√(3×50 ×30×3 × 50 × 10)

=√( 50×50×30 × 30 × 3)

=1500√3 m^2 Answer