 Hello and welcome to the session. In this session we shall discuss the following question and the question says that Ben measured the height of building as 215 feet by using trigonometric results. The actual height of building is 224 feet. Find the percent error in Ben's measurement. Give your answer to nearest tenth of percent. We know that percent error is equal to modulus of approximate value minus exact value upon exact value into 100%. With this key idea let us proceed to the solution. In this question we are given that the approximate height of the building calculated by Ben is equal to 215 feet and the exact height or we can say the actual height of the building is given as 224 feet. So here we are given approximate height of the building equal to 215 feet and the exact height or actual height of the building is given as 224 feet and we need to find the percent error in Ben's measurement. Percent error is given by modulus of approximate value minus exact value divided by exact value into 100%. So percent error will be given by modulus of the approximated value that is 215 minus of the exact value which is equal to 224 divided by the exact value that is 224 into 100%. Which is equal to modulus of 215 minus 224 will be equal to modulus of minus 9 upon 224 into 100%. Which is equal to modulus of minus 9 is 9 upon 224 into 100% and this is equal to 9 into 100 that is 900 by 224% which on further solving gives us 4.01%. That is we get 4.01 by dividing 900 by 224. So we get 4.01% as the percent error and by rounding it to nearest tenth of percent we get 4.0%. Thus we can say the percent error is given by 4% which is the required answer. This completes our session. Hope you enjoyed this session.