Answer:16
Step-by-step explanation:
You have to find B by using a²+b²=c²
a² and b² are legs, the longest is the hypotenuse(c²).
7.8 would be a². B² is unknown and 17.8 is c²
7.8²+b²=17.8²
(7.8²=60.84
17.8²=316.84)
60.84+b²=316.84(What you do on one side you do to the other)
-60.84 -60.84
b²=256(The opposite of squaring it is to find the square root)
√ 256=16
