Answer: 
Step-by-step explanation:
1. You must apply the following formula for calculate the total surface area the regular pyramid:

Where p is the perimeter of the base, l is the slant height and B is the area of the base.
2. The perimeter is, where s is the side length:

3. The faces are isosceles traingles. So, to find the slant height you can divide one base into two equal right triangles and calculate the slant height with Pythagorean Theorem:

4. The base is equal to any face, then both have equal areas. As previously you divide one base into two equal righ triangle to find the slant height, you can calcualte the area of one right triangle and multply it by 2 to calculate B:

Finally substitute values:

Answer:
30 degrees
Step-by-step explanation:
This is an isosceles triangle having 2 equal sides and 2 equal base angles.
since the measurement of all the internal angles of the triangle is 180 degrees and we know that each base angle is 75 degrees
solving for x:
75 + 75 + x = 180 degrees
150 + x = 180
x = 180 - 150
x = 30 degrees
youll get 2and 3/4 then divide by 2 and you get 1.0375=2 and 3/80
hope this helps!