Question

observe the following parallelogram and find the value of the unknowns a,b,and c​

Answer 1

Finding a

2a - 1 = 17 (diagonals intersect each other at the half-way point)

2a = 17 + 1

2a = 18

a = 18/2

a = 9

Finding b

b + 5 = 15 (same rule as a)

b = 15 - 5

b = 10

Finding c

c = 21 (opposite side are equal in parallelogram)