Question

The perimeter of an isosceles triangle is
30 cm. The lenght of its congruent side
is 3cm more
than its base.
find the length
is 8 cm​

Answer 1

Step-by-step explanation:

let the base of the isosceles triangle is x cm

then the length of the congruent sides are each( x+3)cm

so, x+3+x+3+x=30

3x=30-6=24

x=24/3=8

so base is 8 cm

and congruent side is (8+3)cm=11cm

Answer 2

Answer:

Let the congruent sides of an isosceles △ be x.

Let the base of the isosceles △ be y

According to the 1st condition,

x+x+y=30

2x+y=30

According to the 2nd condition

x=y+3

x−y=3

Solving equation (1) and (2)

2x+y=30

x−y=3

-------------------

3x=33

x= 33

3

x=11

By substituting x=11 in equation (1)

2x+y=30

2(11)+y=30

22+y=30

y=30−22

=8

∴ The length of the sides of a △ are 11cm,11cm and 8cm.