Across section of a cone taken perpendicular to the base and intersecting the apex of the cone is what shape? a. square b. triangle c. prism d. oval

B. Triangle

Step-by-step explanation:

Making the cone rest on its base on a flat surface and looking at the cross section from the side, the slant height gives the hypotenuse, the line perpendicular to the base  and joining the center of the base to the apex makes the height while the line joining the slant height to the center of the base gives the base of the right triangle formed.

the infinity sign

step-by-step explanation:

< xcy ≅ < xby

step-by-step explanation:

in δcax and δbax,

so, δcax ≅ δbax (side-angle-side or sas)

since δcax ≅ δbax, we can conclude < acx ≅ < abx

in δacy and δaby,

so, δacy ≅ δaby (side-angle-side or sas)

since δacy ≅ δaby, we can conclude < acy ≅ < aby

now,

< acy ≅ < aby

=> < acx + < xcy ≅ < abx + < xby

=> < acx + < xcy ≅ < acx + < xby   (since < acx ≅ < abx already proved above)

subtracting < acx from both sides, we get

< acx + < xcy -< acx ≅ < acx + < xby -< acx

cancelling out < acx and -< acx from both sides, we get

< xcy ≅ < xby (proved)