I want you to imagine as you read this or you can draw through the help of my explanation and see yourself:
1↪Draw triangle ABC where BC>AC
2↪D is any point on AC such that CD=CB
3↪Roughly drawing , you can assume CD=CB and and join BD
4↪SO triangle ABC which is a big triangle is divided into Triangles ABD and BDC
5↪See in triangle BDC ,CD=CB so, base angles of isosceles triangle are equal:
<CDB=<CBD = x (assume) which means x is acute angle since CDB and CBD are are in same triangle with same measure and there can't be any two obtuse angle in any traingle. So x must be acute.
6↪Now see in traingle ABD,
<ADB=180-<CDB=180-x=obtuse angle
...check yourself ...just subtract any acute angle from 180 you will get only obtuse angle (ie angle greater than 90)
That means in triangle ABD , one angle ADB is obtuse which means remaining <ABD and < BAD are acute. [PROVED]
❇Main Concept Used Here:
↪In any triangle there can be maximum of one obtuse angle...so remaining two must be acute angle otherwise interior angles sum can't be equal to 180.
If you would like to know two equivalent ratios for 12/60, you can calculate this using the following steps:
12/60 = 12/2 / 60/2 = 6/30
6/30 = 6/2 / 30/2 = 3/15
3/15 = 3/3 / 15/3 = 1/5
The result would be 6/30 or 3/15 or 1/5.