Answer:
25.
Explanation:
1. if according to the condition 'm∠2 is three times m∠1', then it is possible to write: 3m∠1=m∠2, then
2. if according to the condition m∠WXZ=m∠1+m∠2, then it is possible to write it as:
m∠WXZ=m∠1+3m∠1; ⇔m∠WXZ=4*m∠1;
3. if according to the condition m∠WXZ=100, then
100°=4*m∠1, then
m∠1=100°:4=25°.