Find the arc length of a semi circle when the diameter is 12

If lmn=xyz, which congruences are true by cpctc? check all that apply

The first week samantha learned to read braille, she could read 10 words per minute. in the second week she increased her speed by 20%. in the third week she increased her speed again by another 25%. how many words could she read per minute by the third week? hurry and tell me!

What is the domain of the step function f(x)=[2x]-1?