I do not know how to solve the second problem; however, I can help solve the first problem. To solve the first problem, use Heron's Formula.
A=√a+b+c2×(a+b+c2−a)×(a+b+c2−b)×(a+b+c2−c)
A = Area
a = side a or 43
b = side b or 2
c = side c or 83
A=√43+2+832×(43+2+832−43)×(43+2+832−2)×(43+2+832−83)
A=√43+63+832×(43+2+832−43)×(43+2+832−2)×(43+2+832−83)
A=√103+832×(43+2+832−43)×(43+2+832−2)×(43+2+832−83)
A=√1832×(43+2+832−43)×(43+2+832−2)×(43+2+832−83)
A=√1832×(43+2+832−43)×(43+2+832−2)×(43+2+832−83)
A=√3×(43+2+832−43)×(43+2+832−2)×(43+2+832−83)
A=√3×(43+63+832−43)×(43+2+832−2)×(43+2+832−83)
A=√3×(103+832−43)×(43+2+832−2)×(43+2+832−83)
A=√3×(1832−43)×(43+2+832−2)×(43+2+832−83)
A=√3×(62−43)×(43+2+832−2)×(43+2+832−83)
A=√3×(186−43)×(43+2+832−2)×(43+2+832−83)
A=√3×(186−86)×(43+2+832−2)×(43+2+832−83)
A=√3×(106)×(43+2+832−2)×(43+2+832−83)
A=√3×(53)×(43+2+832−2)×(43+2+832−83)
A=√3×53×(43+2+832−2)×(43+2+832−83)
A=√31×53×(43+2+832−2)×(43+2+832−83)
A=√153×(43+2+832−2)×(43+2+832−83)
A=√5×(43+2+832−2)×(43+2+832−83)
A=√5×(43+63+832−2)×(43+2+832−83)
A=√5×(103+832−2)×(43+2+832−83)
A=√5×(1832−2)×(43+2+832−83)
A=√5×(62−2)×(43+2+832−83)
A=√5×(3−2)×(43+2+832−83)
A=√5×(1)×(43+2+832−83)
A=√5×1×(43+2+832−83)
A=√5×(43+2+832−83)
A=√5×(43+63+832−83)
A=√5×(103+832−83)
A=√5×(1832−83)
A=√5×(62−83)
A=√5×(3−83)
A=√5×(93−83)
A=√5×(13)
A=√5×13
A=√51×13
A=√53
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