Page:An introduction to linear drawing.djvu/94

 ﻿A few trials will show, that the height required is, 83 nearly, for 83 times 83 are 6889.

4.	The smaller sides of a rectangular scalene trian- gle, (1st Class, fig. 13,) are 5 and 7 inches, required the larger side. Ans. 8,6 in. nearly.

5.	One small side of a rectangular scalene triangle is, 8in-,3 and the other 4in-,8 what is the size of the third side ? Ans. 9,59 in. nearly.

6.	The two equal sides of a rectangular isoceles tri- angle, are 4,8 in length, what is the length of the base ? Ans. 6,785 in. nearly.

7.	The base of a rectangle (Ex.2) is 7,15; the diagonal 13,25 ; required the height (that is, the third side of the triangle.) Ans. 14,14 in. nearly.

8.	The base of a rectangle is 4,75 and the height 7,25 required the diagonal, or longest side of the trian- gle. Ans. 8,67 in. nearly.

9.	What is the height of an isoceles triangle, of which the base is 6 inches, and the equal sides 3in-,8 each i Ans. 2,33 in. nearly.

The instructor may increase these examples at pleas- ure.

Problem II. To find the circumference of a circle. when lengthened out into a right line.

Rule. Multiply its diameter hy 3, and add a sev- enth of a diameter.

Example 1. The diameter of a circle is 4lu-,523.

4,523 3

13,569

A seventh of 4,523 is ,646

The circumference is 14,215