Answer:
1) 13.3 cm
2) 48.3 cm
Step-by-step explanation:
1) Right angled triangle ODC and right angled triangle OAB are similar because AB//DC. The two triangles have the same proportion and are equiangular (having equal angles) but have different lengths.
Let OB = x, OC = OB + BC = x + 8
Therefore:
The height of triangle ODC = OC = x + 8 = 5.3 + 8 = 13.3 cm
2) Using Pythagoras theorem:
OD² = OC² + DC²
OD² = 13.3² + 15²
OD² = 401.89
OD = √401.89 = 20 cm
2) perimeter of triangle ODC = OD + OC + DC = 20 + 13.3 + 15 =48.3 cm