Question

An isosceles triangle has perimeter 30 cm and each of the equal sides is 0.12 m. The third side is​

Answer 1

$Perimeter \: of \: isosceles \: triangle=30cm</p><p></p><p> \\ \\ Length \: of \: equal \: sides=12cm</p><p></p><p> </p><p>\\ \\ Let \: third \: side \: of \: triangle=xcm</p><p>\\ \\According \: to \: problem, \\ \\ x + 12 + 12 = 30 \\ \\ x + 24= 30 \\ \\ x = 30 - 24 \\ \\ x = 6 \\ \\ there \: side \: of \: triangle \: = 6cm \\ \\ use \: herons\: formula \\ \\ \\ area \: of \: triangle \: = \sqrt{s(s - a)(s - b)(s - c)} sq. \: units \\ \\ where \: s \: = \frac{a + b + c}{2} \\ \\ s = \frac{30}{2} = 15 \\ \\ area \: of \: triangle \: = \sqrt{15(15 - 12)(15 - 12)(15 - 6)} {cm}^{2} \\ \\\\ \sqrt{15 \times 3 \times 3 \times 9} {cm}^{2} \\ \\ \\ = 3 \times 3 \times \sqrt{15} {cm}^{2} \\ \\\\ = 9 \sqrt{15} {cm}^{2} \\ \\ area \: of \: triangle \: = \: 9 \sqrt{15} {cm}^{2} </p><p>$