Question

how many sides do 3 heptagons, 1 dodecagon, and 5 nonagons have in all? sides

Explanation:

Step1: Find sides of heptagons

A heptagon has 7 sides. 3 heptagons have $3\times7 = 21$ sides.

Step2: Find sides of dodecagon

A dodecagon has 12 sides. 1 dodecagon has 12 sides.

Step3: Find sides of nonagons

A nonagon has 9 sides. 5 nonagons have $5\times9=45$ sides.

Step4: Calculate total sides

Add up the sides: $21 + 12+45=78$ sides.

Answer:

78