Please help. Find the length of the side labeled x. Round intermediate values ​​to the nearest thousandth. Use the rounded values ​​to value. Round your final answer to the nearest tenth

In the diagram, the measure of angle 9 is 85° which angle must also measure 85°?

In the figure below, ∠dec ≅ ∠dce, ∠b ≅ ∠f, and segment df is congruent to segment bd. point c is the point of intersection between segment ag and segment bd, while point e is the point of intersection between segment ag and segment df. the figure shows a polygon comprised of three triangles, abc, dec, and gfe. prove δabc ≅ δgfe.

Prove that the value of the expression 7^8–7^7+7^6 is divisible by 43.