Question

The perimeter of traingle is 40 cm two of its side measure 12.9 cm and 14.6 cm find the length of its third side

Answer 1

Answer:

12.5

Explanation:

perimeter of triangle =sum of all sides

40=14.6+12.9+x

40=27.5+x

x=40-27.5

x=12.5

Answer 2

Answer: A=hbb

2

A=s(s﹣a)(s﹣b)(s﹣c)

P=a+b+c

s=a+b+c

2

Solving forhb

hb=﹣﹣P4+4P3a+4P3c﹣4(Pa)2﹣12P2ac﹣4(Pc)2+8Pa2c+8Pac2

2a﹣2P+2c=﹣﹣404+4·403·12.9+4·403·14.6﹣4·(40·12.9)2﹣12·402·12.9·14.6﹣4·(40·14.6)2+8·40·12.92·14.6+8·40·12.9·14.62

2·12.9﹣2·40+2·14.6≈12.13366cm