The acute angle of a rectangle of a triangle is 4 times the other acute angle of that triangle.

The acute angle of a rectangle of a triangle is 4 times the other acute angle of that triangle. find the smallest angle of this triangle.

The path that acute angle, which is less, will be equal to the variable a.

Then, in accordance with the conditions of this problem, that acute angle, which is larger, can be represented using the mathematical expression 4a.

Since we know for sure from the school geometry course that in total such angles always give 90 °, we have the opportunity to write down the equation and find out what value the smaller one will be:

a + 4a = 90;

5a = 90;

a = 18.

Answer: With such initial conditions, the desired angle will be equal to 18 °.