Please answer this question:) I need help:(​

9514 1404 393

  (c)  The angles measure 90°.

Step-by-step explanation:

A (convex) quadrilateral with four equal-length sides must be a rhombus, so must have opposite sides parallel and diagonals that are perpendicular bisectors. In order for the rhombus to be a square, its angles must measure 90°.

25.2

step-by-step explanation:

2+4x6-8/10= 25.2

step-by-step explanation:

there is a formula i can give you:

it is r^2*n*sin(360/n) divided by 2 where r represents the "radius" and n is the number of sides.

plug them in:

(10sqrt(3))^2*6*sin(360/6) divided by 2

100*3*6*sin(60) divided by 2

900*sin(60)

900*sqrt(3)/2

450*sqrt(3)

approx is 779.4 cm^2