Given △ABC, AD = 5, BC = 20, AC = 11 BD is an altitude Find: AB

13

Step-by-step explanation:

To find AB, we need to find BD.

Do this by using Pythagorean’s theorem

Square root of 20 squared minus 16 squared =Square root of 400-256 = Square root of 144 = 12cm

Use Pythagorus Theorem to find the measure of AB

AB = √DA^2 + BD^2

AB = √25 + 144

AB = √169 = 13

Hope this helps

0.61 has 2 decimal places, so we put the decimal digits of 0.61, 61 over 1 followed by the number of zeroes equal to the number of decimal places, 

2:     61/1 = 61/100.