\fdO'^ - Old Forge Coal Mines

SURVEYING.
(QUESTIONS 614-705.)
(614) Let ;tr = number of degrees in angle C \
then,
2x = angle A and '6x = angle B. The sum of A, B, and C
[sx + 2x-^dx=6x = 180°, or x-'dO° = C; 2-r = 60° = A,
and dx = 90° = B. Ans.
(615) Let -f = number of degrees in one of the equal
angles; then, 2x = their sum, and 2x X 2 = 4iX = the greater
angle. 'Zx -\- Ax = 6x = sum of the three angles = 180°;
hence, x — 30°, and the
greater angle = 30^^ X 4 =
120°. Ans.
(616) ^^ in Fig. 55
is the given diagonal 3.5 in.
3. 5' = 1 2.25 -f- 2 = 6.125 in.
/6.125 = 2.475 in. = side of
the required square. From
A and B as centers with
radii equal to 2.475 in., de-
scribe arcs intersecting at
C and D. Connect the ex-
tremities A and B with the
points C and D by straight
lines. The figure A C B D is the required square.
(617) Let A B, Fig. 56, be the given shorter side of the
rectangle, 1.5 in. in length. At A erect an indefinite perpendicular
A C to the line A B. Then, from B as a. center
with a radius of 3 in. describe an arc intersecting the perpendicular
A C in the point D. This will give us two