Question

The perimeter of an isosceles triangle is 18 cm. If one of the equal sides is 5¾ cm long,
find the measure of the third side.​

Answer 1

perimeter of isosceles triangle is 2a+b

putting the value perimeter is 18 and one of the equal side is 23/4, we get

        18 = 2×23/4 + b

        b = 18-23/2

        b = (36-23)/2

        b = 13/2 cm

the other side is 13/2 cm

Answer 2

Answer:

Length of third side is 6.5cm

Step-by-step explanation:

C = 18cm.

trngl ABC, AB = 5.75, AC = 5.75

AB+AC+BC = 18

5.75+5.75+BC = 18

11.5+BC = 18

BC = 18-11.5 = 6.5cm