I have tried to solve these but with no luck.

1). Find the area of the following triangles: (Use Logarithms)

a. a=12.7, b=21.5, and c=28.6.
b. c=426, A=45°48'36", and B=61°2'13"
c. An isosceles triangle in which each of the equal sides is 14.72 in.and the vertex angle is 47°28'.


2). Find the radius of the inscribed circle and the radius of the circumscribed circle for the triangle in part a of question 1.

galactus

1a: Use Heron's formula,

A=sqrt(s(s-a)(s-b)(s-c)), where s=semiperimeter.

1c: The area of an isosceles is given by the formula, 1/2r^2sin(theta).

In your case, 1/2(14.72)^2sin(712/15)