Question

An isosceles triangle has perimeter 28 and each of the equal sides is 12 find the
third of side​

Answer 1

Answer:

Perimeter of isosceles triangle=30cm

Length of equal sides=12cm

Let third side of triangle=xcm

According to problem,

x+12+12=30

x+24=30

x=30−24

x=6

∴ Third side of triangle=6cm

Using Heron's formula

Area of triangle=

s(s−a)(s−b)(s−c)

sq. units

where s= 2

a+b+c

s= 2 30 =15

Area of triangle=

15(15−12)(15−12)(15−6)cm 2

=

15×3×3×9

cm

2

=3×3×

15cm 2

=9

15 cm2

∴ Area of triangle=9

15cm2

.

Answer 2

Step-by-step explanation:

GIVEN:

PERIMETER OF AN ISOSCELES TRIANGLE IS 28 CM.

TWO EQUAL SIDES OF EACH =12 CM

TO FIND:

THE THIRD SIDE.

FORMULA USED:

PERIMETER OF A TRIANGLE = SUM OF THREE SIDES.

SOLUTION:

PERIMETER OF TRIANGLE =SUM OF THREE SIDES.

LET THE THIRD SIDE BE X CM.

=>28=12+12+X

=>28=24+X

=>X=28-24=4CM

HENCE THE THIRD SIDE =4 CM.