Answer:
The answer is a. 21.
Step-by-step explanation:
We solve this question by using Pythagoras theorem to relate the sides of a right angled triangle.
Here,
Hypotenuse of the given triangle(c)=75
Two sides of right angled triangle are:
a=72
b=?
Then,
for a given right angled triangle abc,
Using Pythagoras theorem,
Squaring on both sides,
or,
or,
or,
or,
∴
So, the value of b is obtained to 21 by the use of Pythagoras theorem.