Answer:
Yes it forms a right angle triangle.
CosA=(21^2+23^2-25^2)/2*21*23
cosA=345/966
A=cos^-1(345/966)
A=69.08
Answer:
x=38 degrees
Step-by-step explanation:
supplemental angle to 114 degrees is 66 degrees
180=x+2x+66
3x=114
x=38 degrees
The answer must be

since the triangular pyramid has 4 faces and each has an area of 30

we should multiply that by 4 , so :
The answer is £287.98 is the correct answer