Help Please!!!!!!
1 answer:
Answer:
centre = (2, - 1), radius = 6
Step-by-step explanation:
Rearrange the equation by placing the x and y terms together and adding 31 to both sides
Given
x² + y² - 4x + 2y - 31 = 0, then
x² - 4x + y² + 2y = 31
Use the method of completing the square
add ( half the coefficient of the x/y term )² to both sides
x² + 2(- 2)x + 4 + y² + 2(1)y + 1 = 31 + 4 + 1
(x - 2)² + (y + 1)² = 36
The equation of a circle in standard form is
(x - h)² + (y - k)² = r²
where (h, k) are the coordinates of the centre and r the radius
compare to (x - 2)² + (y + 1)² = 36, then
centre = (2, - 1) and r = = 6
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ANSWER
B) A rectangle with a length of 15 cm and a width of 9 cm.
EXPLANATION
The given rectangle, A, has length, 10cm and its width is 6cm.
The rectangle that is similar to rectangle A, has the corresponding sides in the same proportion.
For option A, the triangle has length 9cm and width 6cm.
The ratio of the corresponding sides are:
Since the ratios are not equal, the two triangles are not similar.
For the triangle in option B, the length is 15cm and the width is 9cm.
The ratio of the corresponding sides are:
Since the sides of the triangle are in the same proportion, the two triangles are similar.
For option C, the proportions are not the same.
The proportions are not the same for the triangle in option D.
B) A rectangle with a length of 15 cm and a width of 9 cm.
EXPLANATION
The given rectangle, A, has length, 10cm and its width is 6cm.
The rectangle that is similar to rectangle A, has the corresponding sides in the same proportion.
For option A, the triangle has length 9cm and width 6cm.
The ratio of the corresponding sides are:
Since the ratios are not equal, the two triangles are not similar.
For the triangle in option B, the length is 15cm and the width is 9cm.
The ratio of the corresponding sides are:
Since the sides of the triangle are in the same proportion, the two triangles are similar.
For option C, the proportions are not the same.
The proportions are not the same for the triangle in option D.