We know the perimeter is the total sum of all sides of the shape, we can use this to form an equation: the perimeter=1st side + 2nd side + 3rd side + 4th side 39a-7=9a+(5a+1)+(17a-6)+4th side.
Collect like terms to get 39a-7=31a-5+4th side
If we move everything but the 4th side over to the left we can solve
C. 8a-2=4th side is the correct answer
If you can find one leg of a triangle to be congruent to a leg on the other triangle, then you can use the HL (hypotenuse leg) theorem. If the hypotenuse and one leg of a right triangle are congruent to the hypotenuse and a leg of another right triangle, then the triangles are congruent.
Multiply by a across the formula
Answer:
1. 4.22
2. 19.415
3. nine and thirty- five
4. Three and four hundred twelve
Step-by-step explanation
