Answer:
v=9 cm³
sa=30 cm²
Step-by-step explanation:
v=3*3*1=9cm³
sa=(2*3*3)+(4*3*1)=18+12=30 cm²
We know in these kind of triangles that have a 90 degrees angle, we can do:

so the first question:

and then:

so , when you want to rationalize , usually you must multiply the irrational factor as 1:

so , now multiply:

in the next question,we know negative numbers in radical don't have any solution so 2 is correct,
Answer:
im pretty sure every angle is 80 degrees
Step-by-step explanation:
this is my first day in brainly, so im soo sorry if im wrong
Answer:
12.47 is the correct answer