Answer:
20 cm
Step-by-step explanation:
So to start off we know the hypotenuse is 29 and one leg is 21.
And we the the hypotenuse in an equation is c and the one leg can be b or a but in this situation it is b.
So when putting it into the equation which looks like this.
a^2+ 21^2 = 29^2
We then square 21 and 29 which gets us 441 and 841.
Then to solve an equation we subtract 441 into 841 which gets us 400.
So our equation looks like this now.
a^2 = 400
Now to get rid of the square we find the square root of both sides.
For a squared it cancels the square out and makes it just a and the square root of 400 is 20.
Hence, a the missing led is 20cm.