In triangle stu, u2 = s2 + t2.

which equation is true about the measure of the angles of the triangle?

the measure of angle stu is equal to 100 degrees
the measure of angle sut is equal to 90 degrees
the measure of angle stu plus the measure of angle tsu is equal to 80 degrees
the measure of angle stu plus the measure of angle tsu is equal to 70 degrees

In a column proof the right column states your reasons

He ! a group of farmers planned to clean 80 acres of wheat per day to finish the work on schedule. right before the work started, they received a new piece of machinery that them clean 10 more acres per day than originally planned. as a result of increased productivity in the last day before the deadline they only had to clean 30 acres. how many acres of wheat did the group of farmers have to clean?

Which shows a reasonable estimation for 124% of 42 using the distributive property?