Hello!
∠GCE = 14° (corresponding angles)
∠GEC = 180° - 78° - 14° (sum of angles in a triangle)
∠GEC = 88°
4x + 88° = 180°
4x = 180° - 88°
4x = 92°
x = 23°
Answer:
1) v= 280 in^3 sa= 262 in^2
2) v= 80 in^3 sa= 120 in^2
3) v= 36 in^3 sa= 72 in^2
4) v= 240 in^3 sa= 252 in^2
For the first one, you did good. I will just suggest a couple things.
Statement Reason
JK ≅ LM Given
<JKM ≅ < LMK Given (You did both of these steps so well done.)
MK ≅ MK Reflexive Property (Your angle pair is congruent but isn't one of the interior angle of the triangles you are trying to prove.)
ΔJMK ≅ ΔLKM SAS
Problem 2: (You also have a lot of great stuff here.)
Statement Reason
DE ║ FG Given
DE ≅ FG Given
<DEF≅<FGH Given
<EDF≅<GFH Corresponding Angles (You don't need to know that F is the midpoint but you got corresponding angle pair which is correct.)
ΔEDF≅ΔGFH ASA
<DFE≅<FHG CPCTC
The transformations that can occur to the graph of the function y = cos x that will exhibit changes would be changes to the angle, or changes to the coefficient. The transformations can be viewed as follows:
y = cos x transforms to y = cos (kx)
k > 1 ; a horizontal shrink occurs
0 < k < 1 ; a horizontal stretch occurs
y = cos x transforms to y = A cos x
|A| > 1 ; a vertical stretch occurs
|A| < 1 ; a vertical shrink occurs
The area is 120/(1/4) or 120 x 4 or 480 square inches
the width is 6/(1/2) or 6 x 2 or 12 inches
to find the length, divide the area by the width
480/12= 40
40 inches
Hope this helps :)