Question

area of a triangle of sides 9cm, 12cm, and 15cm

Answer 1

Step-by-step explanation:

$let \: a \: = 9cm \: b \: = 12m \: c \: 15cm \\ half \: perimeter \: (p) = \frac{a + b + c}{2} = 18 \: cm \\ area \: of \: tringle \: = \: \sqrt{p(p - a)(p - b)(p - c)} = \sqrt{18(18 - 9)(18 - 12)(18 - 15)} = \sqrt{18 \times 9 \times 6 \times 3 } = 54 \: {cm}^{2}$

Answer 2

Answer:

(Solving by using heron's formula)

If the sides are 9cm 12cm and 15cm

Semi perimeter=9+12+15/2

=36/2=18

And by herons formula,

area=

$\sqrt{s \times (s - a) \times (s - b) \times ( \sqrt{s - c)} }$

(where s is semi perimeter)

=

$\sqrt{18 \times (18 - 9) \times (18 - 12) \times (18 - 15)}$

$= \sqrt{18 \times (9) \times (6) \times (3)}$

=

$= \sqrt{2916}$

= 54

SO AREA OF TRIANGLE =54cm square

HOPE IT HELPS!!