∠C =∠B -90
∠A+∠B+∠C=180
2*∠EAB+∠B+∠C=180
2*∠EAB+∠B+∠B -90=180
2*(∠EAB+∠B)=270
∠EAB+∠B=135
∠AEC=∠EAB+∠B=135