If a circle has an area of 84π units then what is the measure of its radius in exact units?
a. 2√21 units
b. √ 54 units
C 10.4 units
d. 108 units

Answer quickly please

Iwant to know what 3g+5h+4g-2h is my teacher is too selfish to tell us

Tim's phone service charges $23.06 plus an additional $0.22 for each text message sent per month. if tim's phone bill was $28.56, which equation could be used to find how many text messages, x, tim sent last month?

The figure shows triangle def and line segment bc, which is parallel to ef: triangle def has a point b on side de and point c on side df. the line bc is parallel to the line ef. part a: is triangle def similar to triangle dbc? explain using what you know about triangle similarity. part b: which line segment on triangle dbc corresponds to line segment ef? explain your answer. part c: which angle on triangle dbc corresponds to angle f? explain your answer. asap