This problem becomes easier if we subdivide the figure, find the areas of the resulting figures and then sum them up.
Draw a vertical line straight down from the edge marked "4 cm" towards the edge marked "18 cm." The resulting rectangle on the left is 15.5 cm long and (18 - 7.5) cm wide, or 15.5 by 10.5 cm. Its area is 162.75 cm^2.
Next, find the area of the rectangle on the right of the line we drew. Its width is 7.5 cm and its height (15.5 - 4) cm, resulting in an area of 86.25 cm^2.
Last, add together these two subareas: combine 86.25 cm^2 and 162.75 cm^2. The total area of the composite figure is then 249 cm^2 (answer).
For 336=214.2(t+3) you first divide each side by 214.2. You would get 80/51=t+3, then you would subtract 3 from each side to get the final answer which is -73/51
For 336=367.2(t) you divide 367.2 on both sides, to get the final answer which is 140/153.
