Find y' and use point slope form to find the equation.
Point slope form: y = m(x − x1) + y1
If the graph was concave down, would the tangent line be an over or under-approximation?
The base and height are given on the graph.
Compute y'(1) and use point slope form again to find the equation.
The vertices of the triangle made by the tangent line are (0, 0), (0, t(0)), and (x-intercept of t(x), 0), where t(x) is the equation of the tangent line.
Calculate the area of the triangle using the vertices to determine the dimensions.