Answer:
4
Step-by-step explanation:
P = s+s+s+s
length = 8
8x2=16
24-16=8
8 / 2 = 4
The hardest part is finding the length of the curve at the top. To find arc length, multiply the circumference by the arc angle divided by full angle (360°) in a circle. Or:

x, the arc angle in a semicircle, is 180°.
r, the radius is 7/2 = 3.5.
Now just plug the numbers in and solve for arc length, s.
s = 2π(3.5)(1/2) ≈ 11.00
Now just add up all the sides. 11cm + 10cm + 10cm + 7cm = 38 cm.
% is a number over 100, so 40% is 40/100, which is 0.40.
Answer:
Rectangular Pyramid
Step-by-step explanation:
Rectangular Pyramid-It has 5 faces, 8 edges and 5 vertices.
The angles of a quadrilateral add to 360, so we can solve for x by adding the 4 angle measures together and setting it equal to 360:
90 + 140 + (x - 10) + (x - 20) = 360
Combine like terms:
230 + 2x - 30 = 360
200 + 2x = 360
200 - (200) + 2x = 360 - (200)
2x = 160
Divide both sides by 2:
2x/(2) = 160/(2)
x = 80