1. it is a right triangle so to find WX (hypotenuse) use Pythagorean theorem
x=√(10.5²+12.3²)=16.2
Answer is H
2.correct answer is A,
half of rectangle is right triangle, where a and b is legs and c is hypotenuse , so you can use Pythagorean theorem, and get
c²=a²+b²
