A=8 , b=13, c=13 solve the triangle

Solving the triangle means you are to find A , B and C

and this can be done using cosine rule:

Cos A = b^2 +c^2 - a^2   / 2bc

Cos B = a^2 + c^2 - b^2 / 2ac

Cos C = a^2 +  b^2 - c^2 / 2ab

substituting the values of a , b and c into the formulas above we have

Cos A = 13^2 + 13^2 - 8 ^2 / 2 x 13 x 13

           = 169 + 169 - 64 / 2 x 169

           = 338 - 64  / 338

           = 274/338

therefore A = Cos^-1  274/338

                A = 35.8404

follow the same step to calculate B

Cos B = 64 + 169 - 169/ 2 x 8x 13

Cos B = 64/ 208

       B = Cos^-1 64/ 208

        B =  72. 0797

Since the triangle is isosceles, it implies B = C

Therefore A ≈ 35.8404 , B ≈ 72. 0797 and C ≈ 72.0797

Step-by-step explanation:

180-142=38 for the acute angle next to the entry

90+38=128

180-128=52

a=52

step-by-step explanation: