:SB :SP205024259070205070205024 :SH0729a :SH1033b :SH0534c :SH1632s s :SH1935s :SP217143266143243106217143 :SF H. Perimeters Make sure you know these theorems, definitions and assumptions. A perimeter is the measure in linear units of the distance around an object. NOTE: < = Angle ^ = Degrees 1. Triangle Perimeter = a + b + c 2. Equilateral Triangle Perimeter = 3s :RA :SD 3. Rectangle Perimeter = 2l + 2w = 2 (l + w) 4. Square Perimeter = 4s 5. Circle Perimeter = Circumference (C) C = 2PIr = PId :RA :SB :SC175070200056225070225070 :SH0827r :SH0833r :SH0930n^ :SH1130L :SF 6. Arc (length) is a fraction of the circumference of a circle. n nPIr Length = --- x 2PIr = --- 360 180 NOTE: ^ = Degrees :RA 7. Irregular Figures. To find the perimeter of an irregular figure: a. Compute the perimeters of figures forwhich formulas exist. b. Determine their sum, difference, or fractional parts to obtain the required answer. :RA :SD :Q :SB :SP189071217016252071189071 :SH0232B :SH1027A C :SF 1. The perimeter of {ABC is 36". AB = X + 3, BC = 3X - 9, AC = 2X Find the longest side of the triangle. (a) 5" (b) 7" (c) 14" (d) 10" (e) 12" :RCC 1. (c) 14" Ans. x + 3 + 3x - 9 + 2x = 36 6x - 6 = 36 6x = 42 x = 7 AB = 10", BC = 12, AC = 14 longest is AC = 14" Ans. Note: Perimeter is not = 180^ :RA :SD :Q 2. The distance around a rectangular swimming pool is 250 feet. The pool is 50 feet wide. Find its length. (a) 5' (b) 75' (c) 100' (d) 200' (e) 150' :RCB 2. (b) 75' Ans. Let l = length of pool. 50 + l + 50 + l = 250 100 + 2l = 250 2l = 150 l = 75' Ans. :RA :Q 3. Find the diameter of a quarter-mile circular track. (use PI = 22/7 and express your answer in yards) (a) 20 yd. (b) 40 yd. (c) 70 yd. (d) 140 yd. (e) 240 yd. :RCD 3. (d) 140 yd. Ans. Note: 1/4 mile = 440 yd. c = PId 22 440 = --d 7 140 yd. = d Ans. :RA :Q 4. Find the cost of framing a picture 3 feet by 4 feet at $2.00 per foot. (a) $12.00 (b) $14.00 (c) $24.00 (d) $28.00 (e) $48.00 :RCD 4. (d) $28.00 Ans. Note: Framing is perimeter. p = 3 + 4 + 3 + 4 p = 14 ft. Cost = 14 x 2 = $28.00 Ans. :RA :Q 5. Find the side of an equilateral triangle whose perimeter is equal to that of a square of side 6" (a) 4" (b) 8" (c) 12" (d) 24" (e) 9" :RCB 5. (b) 8" Ans. Note: The perimeter of the square is 24". Therefore the side of the triangle = 24/3/ = 8" Ans. :RA :Q 6. The perimeter of an equilateral triangle equals the perimeter of a square. A side of the triangle is b, and a side of the square is k. Express b in terms of k. (a) 3b/4 (b) 4b/3 (c) 3k/4 (d) 4k/3 (e) 4b/3k :RCD 6. (d) 4k/3 Ans. 3b = perimeter of triangle 4k = perimeter of square 3b = 4k b = 4k/3 Ans. :RA :Q :SB :SP224016189080252080224016 :SP189080189128252128252080 :SH062710" :SH063610" :SH13266" :SH13386" :SH102860^ 60^ :SF 7. Find the perimeter of the accompanying geometric figure. (a) 32" (b) 38" (c) 42" (d) 44" (e) 52" :RCC 7. (c) 42" Ans. The triangle is equilateral since two angles are 60^. Therefore the common line in the triangle and the rectangle is 10", and the base of the rectangle is also 10". 10" + 10" + 6" +10" + 6" = 42" :ET :ET .diclose hbb.int
