aThearea oftriangle is 84 cm. Ifthe length of thesidesareconsecutive naturalnumbers, then whatare the dimensions(in cm) of thetriangle?Please answer it About the author Adalynn
Answer: Let a=n−1,b=n,c=n+1;n∈N and n≥2 ∴ larger angle =C and smallest angle =A Since the sides of triangle are in A.P., then C=2A sinC=sin2A⇒sinC=2sinAcosA ⇒2ac=cosA⇒2bcb2+c2−a2=2ac ⇒(n)(n+1)(n2)(n+1)2−(n−1)2=2(n−1)n+1 ⇒n=5⇒a=4,b=5,c=6 Reply
Answer:
Let a=n−1,b=n,c=n+1;n∈N and n≥2
∴ larger angle =C and smallest angle =A
Since the sides of triangle are in A.P., then C=2A
sinC=sin2A⇒sinC=2sinAcosA
⇒2ac=cosA⇒2bcb2+c2−a2=2ac
⇒(n)(n+1)(n2)(n+1)2−(n−1)2=2(n−1)n+1
⇒n=5⇒a=4,b=5,c=6