Answer:
98 cm
Step-by-step explanation:
sum the parts of the ratio , 2 + 4 + 7 = 13 parts
divide perimeter by 13 to find the value of one part of the ratio.
182 ÷ 13 = 14 cm ← value of 1 part of the ratio , then
2 parts = 2 × 14 = 28 cm
4 parts = 4 × 14 = 56 cm
7 parts = 7 × 14 = 98 cm
the longest side is 98 cm
