Question

2)The edges of a triangular board are 6 cm, 8 cm and 10 cm. The cost of painting it at the rate of 9 paise per sqcm is​

Answer 1

Answer :

Given :

• The edges of a triangular board are 6 cm, 8 cm and 10 cm.

Find :

• The cost of painting it at the rate of 9 paise per sqcm.

Solution :

Let us first ,

• Find the area of the triangle

Here,

• As the triangle is scalene triangle thus, we will use heron's formula.

Let the consider ,

• The triangle as ABC,

♦Using Heron's formula,

S=$\dfrac {AB+BC+AC}{2}$

S=$\dfrac {6+8+10}{2}$

S=$\dfrac {24}{2}$

S= 12

Now,

=$\sqrt {S(S-AB)(S-AC)(S-BC)}$

=$\sqrt {12(12-6)(12-8)(12-10)}$

=$\sqrt {12(6)(4)(2)}$

=$\sqrt {576}$

=24² cm

Now,

• As we have the surface area so, we will now find the cost.

♦Cost of painting :-

= 24 × 9

= 216paise

Now,

Convert it into paise

= 216 ÷ 100

= Rs 2.16.

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