Angle c and angle d are congruent. Congruent means they have the same the measure, or they have EQUAL measures. You set the two values equal to each other and solve for x.
X+26=2x-10 subtract x from both sides
26=x-10 add 10 to both sides
36=x
Now substitute x back in for angle d.
2(36)-10 = 62
The formula for perimeter is
Side a x2 + side b x2
So just multiply 18 by two, and subtract it from 108
We can not see the rest of 12
The lesser of the numbers given are -16 because -16 is more negative.
