How to find the all 4 angles of a trapezoid given only the side lengths

Simplify 4 square root of 2 end root plus 7 square root of 2 end root minus 3 square root of 2 . (1 point) 2 square root of 8 8 square root of 2 8 square root of 6 6 square root of 8

Ahiker stands at an unknown elevation before he ascends 2 miles up a mountain to an elevation of 9 miles. find the elevation of the hiker before his ascent.

Ntriangle abc, m∠a = 35° and m∠b = 40°, and a=9. which equation should you solve to find b?