Question

Find the area of a triangle two sides of which are 18cm and 10cm and the perimeter is 42.

Answer 1

perimeter=1st side +second side +3rd side
perimeter=42
1st side=18
2nd side=10
3rd side=?

42=18+10+3rd side
42-28=14(3rd side)
now ...
semi perimeter (S)=42÷2=21
and
a=18(1st side)
b=10(2nd side)
c=14(3rd side)
By using heron's formula......
Area of triangle =√S(S-a)×(S-b)×(S-C)
area=√21×11×7×3
=√7×3×11×7×3
=7×3√11
area =21√11
21√11=70 approx
so the area is 70unit² approx...


Hope it helps.....
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Answer 2

Answer:

Step-by-step explanation:

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