Question

An issoceles triangle has perimeter 20cm and unequal side is 5cm ,then the length of equal side is a)10 cm b)5cm c)7.5 cm d)7cm class 9​

Answer 1

Answer:

(C) 7.5 CM

Step-by-step explanation:

Let ABC an isosceles triangle where AB=BC.

Perimeter= AB+BC+AC

           20= AB+AB+5 ( AB=BC)

       20-5=2AB

        15/2=AB

         7.5=AB

Answer 2

c) 7.5 cm

Step-by-step explanation:

Let, the equal sides be 'x';

Perimeter= 5cm+x cm +x cm

= (5 + 2x) cm

According to question,

5+2x = 20

2x = 20 - 5

2x = 15

x = 15/2

x = 7.5cm.

By this way we get the value of 'x' as 7.5 cm.

So, Length of the equal sides is 7.5 cm.

Option 'c' is correct.

HOPE I'M HELPING.