To answer this specific problem, the measure of ∡DEF
is 64. I am hoping that this answer has satisfied your query and it will
be able to help you in your endeavor, and if you would like, feel free to ask
another question.

the penalty he'll incurred into, since July 6 is after the deadline of April 15, is I = Prt
now "t" is in years, how many days after April 15 to July 6? well, 15 + 31 + 30 +6, to convert to years, divide by 365
To estimate the quotient, we first round off the divisor and the dividend to the nearest tens, hundreds, or thousands and then divide the rounded numbers. In a division sum, when the divisor is made up of 2 digits or more than 2 digits, it helps if we first estimate the quotient and then try to find the actual number.
71 %
Calculate score for each paper, total them and convert to a percentage.
Paper 1 : mark = 0.65 × 120 =78
Paper 2 :mark = 0.8 ×80 = 64
Total mark = (78 + 64)/200 =142/200
Percentage score = 142/200 × 100 % = 71 %