Question 1060363
{{{drawing(400,1600/9,-1,8,-1,3,
triangle(0,0,7,0,7,2), locate(0,0,B),locate(7,0,C),
rectangle(6.7,0,7,.3),locate(3.3,1.5,"c=?"),
red(arc(0,0,4,-4,0,16)),
locate(7,2.4,A),locate(3.3,0,a=7), locate(7.1,1.2,b=2) )}}}

{{{sec(B)}}{{{""=""}}}{{{HYPOTENUSE/ADJACENT}}}{{{""=""}}}{{{c/a}}}{{{""=""}}}{{{c/7}}}

We need c.  So we use the Pythagorean theorem:

{{{c^2}}}{{{""=""}}}{{{a^2+b^2}}}
{{{c^2}}}{{{""=""}}}{{{7^2+2^2}}}
{{{c^2}}}{{{""=""}}}{{{49+4}}}
{{{c^2}}}{{{""=""}}}{{{53}}}
{{{c}}}{{{""=""}}}{{{sqrt(53)}}}

{{{drawing(400,1600/9,-1,8,-1,3,
triangle(0,0,7,0,7,2), locate(0,0,B),locate(7,0,C),
rectangle(6.7,0,7,.3),locate(3.3,1.7,c=sqrt(53)),
red(arc(0,0,4,-4,0,16)),
locate(7,2.4,A),locate(3.3,0,a=7), locate(7.1,1.2,b=2) )}}}

{{{sec(B)}}}{{{""=""}}}{{{c/a}}}{{{""=""}}}{{{sqrt(53)/7}}}

Edwin</pre></b>