R2+15r+36=0 the answer is r=6
Answer:
Step-by-step explanation:
To copy an angle we follow the following steps,
1). Draw a working line with the help of a straightedge.
2). Now we put a point S as the vertex of the angle.
3). Construct an arc with a radius 'r' (any length ) from vertex S which intersects the working line say at V.
4). With the same radius we draw an arc from point E which intersects the line ED and EF at G and H respectively.
5). Mark an arc from point G which intersects line EF at I.
6). Measure the distance between points G and I with compass and mark an arc from point V which intersects the previous arc say at U.
7). Now join the points S and U.
Hence we copy any angle.
Answer:
10°
Step-by-step explanation:
the sum of interior angles of triangle is 180°
so. 8x+x+90°=180°
9x=90°
x=10°
Answer: 
Step-by-step explanation:
Three-fifths of the sum of 9 and f is
=
=
<u>Answer:</u>

<u>Step-by-step explanation:</u>
Equation of parabola with focus at (0,-4) and directrix is
.
We know that parabola is the locus of all the points such that the distance from fixed point on the parabola to fixed line directrix is the same.
The parabola is opening downwards.
Let any point on parabola is (x,y).
Distance from focus(0,-4) to (x,y) = 







