Solve.
-The equation $D = \frac { 1 } { 2 } \mathrm { n } ( \mathrm { n } - 3 )$ gives the number of diagonals $\mathrm { D }$ for a polygon with $\mathrm { n }$ sides. Find the number of diagonals for a polygon that has 7 sides.

Question

Quizplus · Accepted Answer

Substituting $n = 7$ into the formula $D = \frac{1}{2}n(n - 3)$, we get $D = \frac{1}{2} \times 7 \times (7 - 3) = \frac{1}{2} \times 7 \times 4 = 14$.

Solve -The Equation D=12n(n−3)D = \frac { 1 } { 2 } \mathrm { n } ( \mathrm { n } - 3 )D=21​n(n−3)

Solve
-The Equation $D = \frac { 1 } { 2 } \mathrm { n } ( \mathrm { n } - 3 )$