Question

please solve it's my question please help me to everyone class ninth math ​

Answer 1

Answer:

1st question

Step-by-step explanation:

42= 18+10+x

x=14

by heron's formulae=

root over 21× (21-18)×(21-14)×(21-10)

= root over 4851

Answer 2

Step-by-step explanation:

area of triangle = 1/2×b×h

= 1/2× 18×10

= 90cm

perimeter = 45

let a= x

b=x+1

c=x+2

x+x+1+x+2=45

3x+3=45

3x=45-3

3x=42

x=42/3

x=14

14+1 =15

14+2= 16

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