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The ratio of the lengths of corresponding sides in similar figures (same shape but different size) is called scale factor. It may be expressed as a fraction, decimal, percent, or whole number.
The scale factor from Fig A to Fig B is 3/6 = ½. The scale factor from Fig B to Fig A is 6/3 = 2 6 cm 3 cm Fig A Fig B
A rectangle has sides of 3 cm and 5 cm. A similar rectangle is dilated with a scale factor of ½. Find its length and width. 6 cm by 10 cm 2 cm by 3 cm 1.5 cm by 2.5 cm 2 cm by 2.5 cm
A rectangle has sides of 3 cm and 5 cm. A similar rectangle is dilated by a scale factor of 2. Find its dimensions. 6 cm by 10 cm 2 cm by 3 cm 1.5 cm by 2.5 cm 2 cm by 2.5 cm If we know one shape's perimeter and the scale factor, we can find the other shape's perimeter by multiplying the original perimeter by the scale factor. If the first shape has a perimeter of 16 cm and is dilated by a scale factor of ½, the second shape's perimeter is... Perimeter = 16 80 cm 5 32 cm 3 8 cm 2.5 80 cm 1.5 If the perimeter is of a shape is 16 cm and is dilated with scale factor of 2, the perimeter of the similar shape is... 8 cm 5 32 cm 3 80 cm 3200 cm 45 square centimeters 32 square centimeters Since area is measured in square units, the scale factor needs to be squared before multiplying it by the area of the first shape to find the area of the dilation. Our original shape is 3 cm by 5 cm. Therefore the area is 3 x 5 or 15 square centimeters. A similar shape dilated with a scale factor of 3 will have an area of... 5 3 90 square centimeters 135 square centimeters 5(3) 3(3) If the original area of a shape is 32 square centimeters and is dilated by a scale factor of ¼, the new shape's area would be... 8 8 2 square cm 4 square cm 32 square cm 64 square cm 8(¼) 8(¼) The formula for the circumference of a circle C=2∏r when ∏=3.14. Find the circumference of a circle with a radius of 2 inches dilated by a scale factor of 3. C=2(3.14)(2) C=12.56 2 C=2(3.14)( ) C = The area of a rectangle is 12 inches squared. The rectangle is dilated by a scale factor of ½. What is the area of the new rectangle? inches squared The perimeter of a triangle is 9 cm. The triangle is dilated by a scale factor of 2. Find the perimeter of the new triangle. cm The area of a square is 64 square inches. The square is dilated by a scale factor of 2. What is the area of the new square? square inches Figure A is dilated creating Fig B.
What is the scale factor from Fig A to Fig B?
What is the perimeter of Fig B?
What is the area of Fig B? Fig A 9 9 Fig B square units 3 units 3 Figure A is dilated creating Fig B.
What is the scale factor from Fig A to Fig B?
What is the perimeter of Fig A?
What is the perimeter of Fig B? Fig A 3 3 Fig B 9 square units units 9 Figure A is dilated creating Fig B.
What is the scale factor from Fig A to Fig B?
What is the area of Fig A?
What is the area of Fig B? Fig A 3 3 Fig B square units square units 9 9 A rectangle is dilated with a scale factor of 3. Which statement correctly describes the perimeter of the new figure? The new perimeter is 1/9 times the original The new perimeter is 1/3 times the original The new perimeter is 3 times the original The new perimeter is 9 times the original A rectangle is dilated with a scale factor of 3. Which statement correctly describes the area of the new figure? The new area is 1/9 times the original The new area is 1/3 times the original The new area is 3 times the original The new area is 9 times the original A rectangle is dilated with a scale factor of ⅓. Which statement correctly describes the area of the new figure? The new area is 1/9 times the original The new area is 1/3 times the original The new area is 3 times the original The new area is 9 times the original A rectangle is dilated with a scale factor of ⅓. Which statement correctly describes the perimeter of the new figure? The new perimeter is 1/9 times the original The new perimeter is 1/3 times the original The new perimeter is 3 times the original The new perimeter is 9 times the original |