What is 5.27 × 1021 expressed in standard notation?

The exponent of 21 tells you to move the decimal point 21 places to the right. Since there are only 2 numbers following the decimal we have to add 19 zeros.
5,270,000,000,000,000,000,000

Okay so for every triangle has three angles that always add up to 180 degrees. and to tell the difference between whether they are secure, right or obtuse is that acute: has one angle that is less than 90 degrees. right triangle means there is at least one angle that is exactly 90 degrees. and an obtuse angle has an angle that is bigger than 180 degrees. i’ll do #13 as an example: 13. 40 and 50 so if every triangle has 180 degrees 40+50= 90 degrees then180-90= 90 degrees so the third angle is 90 degrees and because this triangle has a 90 degree angle it means it is a right triangle