Question

the perimeter of an isosceles triangle is 40 cm if 3 times the base is equal to 4 times the congruent side find the length of each side of the triangle

Answer 1

Let two equal side be a
Let base be b
2a + b = 40 (given)
So
b = 40 - 2a ___(1)
Now
3b =4a____(2)
Substitute (1) in (2)
3(40-2a) = 4a
120 -6a = 4a
10a = 120
a = 12 cm
So by (1) or (2)
b = 16 cm

Please say thanks for the hard work

Answer 2

Answer:

let the length of each side be a and bace be b

condition 1 ,

perimeter of isosceles triangle =40 cm

therefore , 2a + b =40 - - - (1)

condition 2,

3b=4a

therefore , 4a-3b=0 - - - (2)

Multiply eq (1) by 3 and eq (2) by 1 ,

6a+3b=120 - - - (3)

4a-3b=0 - - - (4)

Add eq (3) and (4)

6a+3b=120

4a-3b=0

therefore , a=12

put a=12 in eq (1)

2a+b =40

2×12 + b =40

24 +b =40

b=40-24

b=16