Answer:
Center = (5, -2) and radius = √33
Step-by-step explanation:
The equation of a circle is given by the formula;
(x-a)² + (y-b)² = r² ; where (a,b) is the center of the circle and r is the radius of the circle.
In this case;
2x² - 20x + 2y² + 8y =40 ;
Dividing both sides of the equation by 2 we get;
x² - 10x + y² + 4y = 20
we can then use the completing the square on both x and y terms.
x² - 10x + y² + 4y = 20
x² + 2(-5)x + 25 + y² + 2(2) y + 4 = 20 +9 + 4
In standard form we get;
(x-5)² + (y+2)² = 33
Therefore;
Center = (5, -2) and radius = √33
Answer:
Step-by-step explanation:
Area = 1/2 * 2b * (5b - 7)
Area = 1/2 * 2b * (5b - 7) = 24
b * (5b - 7) = 24
5b^2 - 7b = 24
5b^2 - 7b - 24= 0
(b- 3 )(5b + 8) = 0
b = 3 This the only solution that works. b can't be minus
The base is 2b or 2 * 3 = 6
1. Angles ADC and CDB are supplementary, thus
m∠ADC+m∠CDB=180°.
Since m∠ADC=115°, you have that m∠CDB=180°-115°=65°.
2. Triangle BCD is isosceles triangle, because it has two congruent sides CB and CD. The base of this triangle is segment BD. Angles that are adjacent to the base of isosceles triangle are congruent, then
m∠CDB=m∠CBD=65°.
The sum of the measures of interior angles of triangle is 180°, therefore,
m∠CDB+m∠CBD+m∠BCD=180° and
m∠BCD=180°-65°-65°=50°.
3. Triangle ABC is isosceles, with base BC. Then
m∠ABC=m∠ACB.
From the previous you have that m∠ABC=65° (angle ABC is exactly angle CBD). So
m∠ACB=65°.
4. Angles BCD and DCA together form angle ACB. This gives you
m∠ACB=m∠ACD+m∠BCD,
m∠ACD=65°-50°=15°.
Answer: 15°.
Answer:
31.5
Step-by-step explanation:
