Question

find the area of triangle two sides of which are 18 cm and 10 cm and the perimeter is 42 cm?​

Answer 1

Answer:

21√11cm

Step-by-step explanation:

18+10+c=42cm

c=42-28=14cm

so area of triangle

s= 42/2=21cm

s-a= 21-18=3cm

s-b=21-10=11cm

s-c=21-14=7cm

Area of triangle= √21×3×11×7=21√11 cm

Ok

Answer 2

Answer:

two sides of a triangle are 18cm and 10 cm

perimeter is 42 cm

so another side is {42-(18+10)}cm

=(42-28)cm

=14cm

half of the perimeter is 42/2cm=21cm

so area of the triangle is

=√21(21-18)(21-10)(21-14)sqcm

=√21.3.11.7sqcm

=21√11sqcm