Answer:
A) 220.5 mm^2
Step-by-step explanation:
<u>Explanation</u>:-
Given A regular triangular pyramid has a base of area is 31.5mm^2
and also given surface area of triangular pyramid is 252 mm ^2
by using formula
surface area of regular triangular pyramid = base of area + half of lateral surface.

252 = 31.5 + 

220.5 = lateral area of triangular pyramid
lateral area of triangular pyramid = 220.5 mm^2
Answer:
A.
Step-by-step explanation:
as u can see,the other acute angle is 43° and the other is also an acute angle and acute angles must not surpass until 80° meaning, the other acute angle is 47°
Answer:
feet cubic
Step-by-step explanation:
Answer:
D. 
Step-by-step explanation:
The point-slope form of a line is given by:

The line given to us has equation;
.
The slope of this line is -4. The of the line perpendicular to this line is the negative reciprocal of the slope of the given line.
Our slope of interest is therefore; 
Since the point goes through (-2,7), we have
.
We plug in the slope and the point into the point-slope formula to obain;

The required equation is:

Bro I think you should search algerba calcautor and then you'll get the answers