Question

Page
Find the area of triangle whose
sides are 9cm, 12cm and 15cm​

Answer 1

answer :

Area of triangle √s (s-a) (s-b) (s-c)

a = 9 cm , b= 12 cm , c= 15 cm    

 s= a+b+c/2       =  9+12+15/2

                            = 36/2        = 18 cm

Area = √18 (18-9) (18-12) (18-15)

        =√18 x 9 x 6 x 3

        = √9 x 2 x 9 x 3 x 2 x 3

        = 3 x 2 x 9

Area = 54 cm²

Answer 2

Question:

• Find the area of triangle whose  sides are 9cm, 12cm and 15cm​.

Solution:

Need to find: Area of triangle

Step-by-step explanation:

Area of triangle = $\rm{\frac{1}{2}\times b \times h}$

Let us apply the known values,

$:\implies\sf{A^2+B^2=C^2}\\ \\:\implies\mathfrak{9^{2}+12^{2} =15^{2} }$

• Let us consider that, b = 9 and h = 12.

$:\implies\sf{A} = \mathfrak{\frac{1}{2}\times 9\times 12 }\\ \\:\implies\sf{A} = \mathfrak{\frac{1}{2}\times 108}\\ \\:\implies\sf{A} = \mathfrak{\frac{108}{2}} \\ \\:\implies\bigstar\underline{\boxed{\sf{A} = \mathfrak{54 \:cm^2}}}\bigstar$

• Therefore,the area of triangle is 54 cm².

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