Consider a right angle triangle ABC. The hypotenuse AC is equal to 27 and base AB is equal to 13. Then according to Pythagoras theorem;

AC

BC

BC

BC

BC

BC= 23.66

Angle B is 90

CosA= AB/Ac

CosA=13/27

A= because

A= 61.22

As we know;

A + B + C = 180

61.2 + 90 + C=180

C= 28.78

AC

^{2}= AB^{2}+ BC^{2}BC

^{2}= AC^{2}- AB^{2}BC

^{2}= 27^{2}- 13^{2}BC

^{2}= 729 - 169BC

^{2}= 560BC= 23.66

Angle B is 90

^{o}then angle A and angle C are;CosA= AB/Ac

CosA=13/27

A= because

^{-1}[13/27]A= 61.22

^{o}As we know;

A + B + C = 180

^{o}61.2 + 90 + C=180

C= 28.78

^{o}