Question

a isosceles triangle of perimeter is 30cm,and his equal side is 12cm . find tha area of this triangle​

Answer 1

A≈40.25cm²

is the answer

Answer 2

Step-by-step explanation:

$the \: perimeter \: of \: isosceles \: triangle \: = 2s \\ side = 15cm \\ the \: equal \: side \: = 12cm \\ the \: base = 30 - 2 \times 12 = 6cm \\ by \:herons \: formula \: = 15(15 - 12)(15 - 12)(15 - 6) \times 0.5 \\ = (15 \times 3 \times 3 \times 9) \times 0.5 \\ = 34.85685012 \: sq \: cm.$