Question

21. The edges of a triangular board are 6cm , 8cm and 10 cm. find the cost of painting at the rate of Rs0.09 per cm
square.​

Answer 1

Answer:

$\huge \fbox \red{27.996 rupees}$

Step-by-step explanation:

Sizes of the triangle = 6 cm, 8 cm, 10 cm

We will apply the Herons Formula

$s = \frac{a + b + c}{2} \\ \\ = \frac{6 + 8 + 10}{2} \\ \\ = \frac{24}{2 } \\ \\ = 12 \: cm$

S stand semi perimeter.

$AREA = \sqrt{s(s - a)(s - b)(s - c) } \\ \\ = \sqrt{24(24 - 6)(24 - 8)(24 - 10)} \\ \\ = \sqrt{24 \times18 \times 16 \times 14 } \\ \\ = \sqrt{6 \times 2 \times 2 \times 6 \times 3 \times 2 \times 2 \times 2 \times 2 \times 7 \times 2} \\ \\ = 6 \times 2 \times 2 \times 2 \sqrt{3 \times 7 \times 2} \\ \\ = 48 \sqrt{42}$

Hence the area of the given traingle is 48√42

cost of painting at the rate of Rs0.09 per cm

square. = 0.09 x 48√42

= 27.996 rupees

Answer 2

please mark the above answer as brainliest ❣️