Answer:
3
Step-by-step explanation:

Step-by-step explanation:
d=20
r=10
π=3



0.25r-0.125+0.5r=0.5r
0.75r-0.125=0.5r
-0.125= -0.25r
r=0.5
Answer:
A = bh thus: A=671.34 mm²
Step-by-step explanation:
Area =b* (base) h (Height)
ANSWER

EXPLANATION
A) From the diagram, we see that the base of the triangular face is 4 cm long and the height of the triangular face is 3 cm.
B) From the diagram, we see that the length of two of the rectangular face is 15 cm and the width of the rectangular face is 5 cm.
The third rectangular face has a length of 15 cm and a width of 4 cm.
C) The surface area of the prism is the sum of the areas of the faces of the prism.
The area of a triangle is given as:

where b = base, h = height
The area of a rectangle is given as:

where l = length, w = width
Therefore, the surface area of the prism is: