Question

solve it fast please

Answer 1

Answer:

perimeter of triangle- sum of all sides

so, perimeter-3+4+5-12m

now,area-as picture show,it is a scalane triangle so aply the formula of ar(scalane triangle) or by heron's formula. i.e. s=a+b+c/2 & then u have to apply another formula that I have uploaded in my answer and then you will get ur final answer.

Thanks!!

rate my answer please

Answer 2

Answer:

a) 864cm .

b) 28.8cm .

Step-by-step explanation:

let sides be 3x ,4x and 5x.

3x+4x+5x=144

12x=144

x=144/12

x=12 m.

∴Sides are of 36 , 48 ,60.

S= a+b+c/2

S=144/2

S=72

a)   Area =√s(s-a)(s-b)(s-c)

=√72(72-36)(72-48)(72-60)

=√72 (36) (24) (12)

=√12×6×12×3×12×2×12×1

=12×12×6

=144×6

=864 cm²

b)

Ar(ΔABC)=1/2×b×h

864=1/2×60×h [Largest side is 60 cm.]

864=30×h

h=864/30

h=28.8cm