bonjour
8/15 - 5/12 = 32/60 - 25/60
= 7/60
6/14 - 2 = 6/14 - 28/14 = - 22/14 = - 11 /7
5/12 = 6.25/15
6/8.4 = 5/7
7.5² = 6 ² + 4.5 ²
56.25 = 36 + 20.25
56.25 = 56.25 donc le triangle abc est rectangle ⇔ acd est aussi rectangle
ad² = 6 ² + 8 ²
ad² = 36 + 64
ad² = 100
ad = √100 = 10
12.5 ² = 10 ² + 7.5 ²
156.25 = 100 + 56.25
156.25 = 156.25 ⇔ abd est rectangle en a
aire abd = (10 * 7.5) / 2 = 75/2 = 37.5
seconde manière, tu additionnes l'aire des 2 triangles
