ABSTRACT
Problem 1. The area A of a triangle is given by A = 1
2 bh. The base b when measured is found to be
3.26 cm, and the perpendicular height h is 7.5cm. Determine the area of the triangle.
Area of triangle= 1 2 bh = 1
2 × 3.26× 7.5
= 12.225cm2 (by calculator). The approximate values is
1 2
× 3× 8 = 12cm2, so there are no obvious blunder or magnitude errors. However, it is not usual in a measurement type problem to state the answer to an accuracy greater than 1 significant figure more than the least accurate number in the data: this is 7.5 cm, so the result should not have more than 3 significant figures. Thus, area of triangle = 12.2 cm2
Problem 2. State which type of error has been made in the following statements: (a) 72× 31.429= 2262.9 (b) 16× 0.08× 7= 89.6
(c) to 4 decimal places.
