1. (10%) Suppose \( X_1 \), \( X_2 \) are independent and both follow continuous uniform distribution U(0,1). Please find the probability \( Pr(X_1^2 + X_2^2 < 1) \).
1. (10%) Suppose \( X_1 \), \( X_2 \) are independent and both follow continuous uniform distribution U(0,1). Please find the probability \( Pr(X_1^2 + X_2^2 < 1) \).