Question 1079406

△ABC is a right triangle with right angle at ∠{{{B}}} .

{{{AB=42cm}}}
{{{BC=34cm}}}

first find hypotenuse {{{AC}}}

{{{(AC)^2=(AB)^2+(BC)^2}}}
{{{(AC)^2=(42)^2+(34)^2}}}
{{{(AC)^2=1764+1156}}}
{{{(AC)^2=2920}}}
{{{AC=sqrt(2920)}}}
{{{AC=54.04}}}
{{{AC=54}}}

now use {{{sin(A)=AB/AC}}}

{{{sin(A)=42/54}}}

{{{sin(A)=0.78}}}

{{{A=sin^-1(0.78)}}}

{{{A=51.26}}}°

to the nearest degree {{{A=51}}}°