Tromika wants to calculate the area of the isosceles triangle at right. Homework Help ✎
She decides to start by drawing a height from vertex A to side BC as shown below. Will the two smaller triangles be congruent? In other words, is ∆ABD ≅ ∆ACD? Why or why not?
What is m∠DAB? BD?
Determine AD. Show how you got your answer.
Calculate the area of ∆ABC.
Look at the two triangles that are created. They share a side, and the ticks marks mean the sides are equal. How could they be congruent?
Yes, they are congruent by HL≅.
If the segment (height) bisects both ∠BAC and segment BC, how can you calculate the measure of half of each?
∠DAB = 18°
BD = 4
Which trig ratio can you use to determine this length?
How do you find the area of a triangle? Do you have enough information to calculate the area?