Answer:Volume: 85.2 meters^3; Surface area: 123 meters^2Missing angle: 39 degreesStep-by-step explanation:First problem: VolumeThe volume of a rectangular prism, which is what this figure is, is given by the formula: l * w * h (length * width * height).These values are all given in the figure; for length we have 7.1 m, for width we are given 4 m, and for height we are given 3 m.Multiply these given values together.7.1 * 4 * 3 = 85.2The volume of the figure is 85.2 meters^3.Surface areaThe surface area of a rectangular prism is given by the formula: 2(l * w) + 2(l * h) + 2(w * h). In other words, 2 times length * width, 2 times length * height, and 2 times width times height.The length of the figure is 7.1 m, the height is 3 m, and the width is 4 m. Substitute these into the formula.2(7.1 * 4) + 2(7.1 * 3) + 2(4 * 3)Evaluate and simplify.123.4 meters^2Second problem:A triangle's interior angle measurements add up to 180 degrees, and you are given two out of the three angles. To find the measure of the third angle, you would add up the known angles and subtract these from 180 degrees to find the measure of the unknown angle.The equation would look like:x + 90 + 51 = 180Combine like terms.x + 141 = 180Subtract 141 from both sides of the equation.x = 39 degreesThe missing angle has a measure equal to 39 degrees.