Question

Помогите решить задачу. геометрия 7 класс.-------- В треугольнике АВС *угол* С=90°,*угол* А=70°,СД бессектрисы. найдите углы ВСД

Answer 1

Угол С равен 90 градусов, следовательно угол ДСВ равен половине угла С т.е 45 градусов.
угол В равен 90-70=20 градусов.
Угол СДВ равен 180-20-45=115 градусов
угол АДС равен 180-45-70=65 градусов

Answer 2

Problem Statement

В треугольнике АВС угол С = 90°, угол А = 70°, СД - биссектриса. Найдите углы ВСД.

Solution

To find the angles ВСД, we need to use the properties of a triangle and the given information.

Let's break down the problem step by step:

1. We know that angle С is a right angle (90°) and angle А is 70°. 2. We are given that СД is the bisector of angle С. This means that angle ВСД is divided into two equal angles: ВСД = ВСА = ДСА.

To find the value of angle ВСД, we need to find the value of angle ВСА or angle ДСА.

Let's calculate the value of angle ВСА:

1. Since angle С is a right angle, angle ВСА is the complement of angle А. The sum of the measures of complementary angles is 90°. 2. Therefore, angle ВСА = 90° - 70° = 20°.

Since angle ВСА and angle ДСА are equal, we can conclude that angle ВСД = angle ВСА = angle ДСА = 20°.

Therefore, the value of angle ВСД is 20°.

Answer: The value of angle ВСД is 20°.

Explanation

In the given triangle АВС, angle С is a right angle (90°) and angle А is 70°. СД is the bisector of angle С. We need to find the value of angle ВСД.

To solve this problem, we used the following steps:

1. Angle ВСА is the complement of angle А, as angle С is a right angle. The sum of the measures of complementary angles is 90°. 2. Therefore, angle ВСА = 90° - 70° = 20°. 3. Since СД is the bisector of angle С, angle ВСД is equal to angle ВСА and angle ДСА. 4. Therefore, angle ВСД = angle ВСА = angle ДСА = 20°.

Thus, the value of angle ВСД is 20°.

I hope this helps! Let me know if you have any further questions.