Page Three Problem 5: 'A carpenter is planning a set of stairs that need to reach up to a doorway 1.2 metres off the ground. The distance from the building along the ground will have to be 1.8 metres. What will the angle between a stringer and the ground be, to the nearest whole degree?'      Here is the diagram with only the essential information,      along with the side labels: The solution is at the left. Some notes: We show the decimal unrounded, to 8 d.p. The actual calculation would probably not show a decimal, but be carried out using the 'ans' key, or even in one step as 2ndFtan(1.2/1.8) We use notation '2ndF' for a reverse tan, consistent with our use of the Ti33/34 calculator on other pages. Problem 6: No word problem this time, just a diagram. The goal is to find the value of θ to the nearest whole degree. Because the entire triangle does not have a right angle, we'll have to solve this in two parts. Let's solve the left triangle first. We'll solve for the side in the centre, marked 'X' and then use that value in the triangle on the right to find θ: Again carrying two decimal places, we'll use that value in the triangle on the right: Page 1 | Page 2 | Page 3 Resources Content, HTML, graphics & design by Bill Willis 2023