Question

Find the area of an isosceles triangle each of whose equal sides measures 9 cm and whose base is 12 cm.
•18√3
•18√5
•18√6
•18√2​

Answer 1

Answer:

We have,

Three sides13cm,13cm and 20cm.

By using Heron's formula

We need to get the semi-perimeter

s=

2

a+b+c

=

2

13+13+20

=

2

46

=23

Now,

put the heron's formula,

s=

s(s−a)(s−b)(s−c)

=

23(23−13)(23−13)(23−20)

=

23×10×10×3

=10

23×3

=83.07cm

2

Answer 2

SOLUTION :

★Area of traingle is $\sqrt{s( s-a)(s-b)(s-c)}$

↝a = 9

↝b = 9

↝C = 12

↝s = a + b + c / 2

= 9 + 9 + 12/2

= 15

★Now :Area is --

↝$\sqrt{s( s-a)(s-b)(s-c)}$

↝ $\sqrt{15( 15-9)(15-9)(15-12)}$

↝ $\sqrt{15( 6)(6)(3)}$

↝ $\sqrt{15×6×6×3}$

↝ $\sqrt{ 3×5×6×6×3}$

↝ 6×3√5

↝ 18√5

★Area of traingle is : $\sf\red{18√5}$

→Your answer is : option ( B )

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