Stránka:roll 1916.djvu/229

Things to Know and Do 205 the distance between the peg and the tree is to the height of the tree or BA: AC:: BE:X. This may be proved by selecting a knot on the tree which may be easily climbed to. See inside line. To Measure the Distance Across a Stream Drive a stake at H. To measure distance from H to D cut three straight poles of exactly the same length and peg them together in a triangle. Place the triangle on the bank at A, B, C, aghting the line A B for the spot at D, and put three pegs in the ground exactly under the three pegs where the triangle is. Move the triangle to E F G and placing it so that F G should line with A C, and E G with D. Now A G D almost must be an equilateral triangle; therefore, according to arithmetic, the line D H must be seven-deaths of A G, wbidi can of course be easily messured.