View Compilation Error

0_0_38021123_18088.cpp: In function 'double area(double, double, double)':
0_0_38021123_18088.cpp:22:5: error: expected ',' or ';' before 'double'
     double t2=acos(y);///计算出d与r2所夹角
     ^
0_0_38021123_18088.cpp:23:27: error: 't2' was not declared in this scope
     return r1*r1*t1+r2*r2*t2-d*r1*sin(t1);///容斥原理，相交的面积等于两扇形面积减去三角形面积
                           ^