What is the measure of angle ACB?
A
108°
145°

40 & 50 in the right corner are the complementary angles as when placed in a sum (added together) they make 90°

First step is to get rid of the square root. remember that a square root is the same as raising to the (1/2) power. see below: multiply exponents per exponent rules to get: remember you subtract exponents from the denominator and add exponents in the numerator so: simplify further: so a is the correct choice. if you don't understand this google exponent rules and it will you understand. look at the image results.