9.2 x 13.8 = 126.96, now usually to get the area of a triangle we would half this but because we have two of the same triangle we would then have to double it again so they cancel each other out. We then do 6.9 x 9.2 which equals 63.48 and again we have two of the same triangle so no need to half it. So we add the two totals of 126.96 and 63.48 together to get 190.44.
Dear SailorMars, #4's question is very convoluted so I won't show you how to do it. Luckily, I do know how to do #5 and #6. With #5, multiply 8 5/6 by two to get 17 2/3, then do 50-17 2/3 to get 32 1/3 ft of tape. With #6, add 11 1/2 and 6 4/5 to get 18.3 gallons of gas, then do 18.3-3 3/10 to get 15 gallons of gas used.
All triangles have to equal 180 degrees. 52+34 equals 86. 180-86=94. So the angle must measure 94 degrees. =) Looks like you would've selected the right answer. =D