Question

7. The perimeter of a triangle is 47cm. If the longest side of the triangle is 4 cm less than threetimes the shortest side and the third side is 6 cm more than the shortest side how long is the thirdside of the triangle?

Answer 1

Let

x -----> the longest side of the triangle

y -----> the shortest side

z -----> the third side

we have that

the perimeter P is equal to

P=x+y+z

P=47 cm ----> given

so

x+y+z=47 ------> equation A

x=3y-4 ------> equation B

z=y+6 -----> equation C

substitute equation B and equation C in equation A

(3y-4)+y+(y+6)=47

solve for y

5y+2=47

5y=45

y=9 cm

Find out the value of z

z=y+6

z=9+6=15 cm

therefore

the third side is 15 cm long