Trying to estimate the numbers 286,174+35,252+30,796 to see if my answers are reasonable when the numbers are all added up

What is the sum of these mixed numbers 2 1/8 + 4 3/8

Atriangular field has sides of lengths 21, 39, and 41 yd. find the largest angle. (round your answer to the nearest degree.)

Rhombus adef is inscribed into a triangle abc so that they share angle a and the vertex e lies on the side bc . what is the length of the side of the rhombus if ab=c, and ac=b.