I'll start 18 and 22 for you, and you should then be able to do the rest on your own!
For 18, what we literally do is apply the distance formula for all the points and add them up. For B to C, we get the distance between them to be
sqrt((x1-x2)^2+(y1-y2)^2)=sqrt((0-4)^2+(3-(-1))^2)=sqrt((-4)^2+4^2)=sqrt(16+16)=sqrt(32). Repeat the process for C to E, E and F, and F to B then add the results up to get your answer!
For 22, since the area of a rectangle is length*width (we know given the right angles and that the opposite sides are equal in how long they are), we can multiply 2 perpendicular lines, for example, BC and CE to get sqrt(32)*sqrt(8)=16 as the area
= -10x^2 - 6xy + 6xz
hope it helps
Answer:
1)Area; A = ¼πr²
Perimeter; P = πr/2 + 2r
2)A = 19.63 cm²
P = 17.85 cm
3) r = 8.885 cm
4) r = 14 cm
Step-by-step explanation:
This is a quadrant of a circle. Thus;
Area of a circle is πr². A quadrant is a quarter of a circle. Thus;
Formula for Quadrant Area is; A = ¼πr²
A) Perimeter of a circle is 2πr. Thus, perimeter of a quadrant is a quarter of the full circle perimeter.
Formula for the quadrant perimeter in the image given is;
P = 2πr/4 + 2r
P = πr/2 + 2r
B) When r is 5 cm;
A = ¼π(5)²
A = 19.63 cm²
P = π(5)/2 + 2(5)
P = 17.85 cm
C) when A is 100cm²:
¼πr² = 100
r² = 100 × 4/π
r² = 78.9358
r = √78.9358
r = 8.885 cm
D) when P = 50 cm.
50 = πr/2 + 2r
50 = (½π + 2)r
r = 50/(½π + 2)
r = 14 cm